This is a set of rough notes, assembled from my own research while painting a few hundred 25s for the conflict. Hopefully, I will have a chance to extend and organize this material in future, but for the time being I offer this brief summary based on what I have learned to date. It is by no means comprehensive, conclusive, or even necessarily correct. My apologies - if you have better information, please contact me!
The Mexican Revolution was fought by a mixture of untrained rebels - the bulk of the forces who fought for Villa and Zapata initially were in this class - and professional soldiers. For the majority of the war, however, the tactics were those of the pre-WWI era. Although machineguns were common (Lewis guns, Gatlings, Colts, etc.), modern rifles were the norm (Mausers, 1902 Springfields, and Winchesters were the typical weapons - all breech-loading magazine-fed repeaters), and the artillery was modern (French/Mondragon 75mm and 80mm, along with some smaller breach-loading mountain guns, the odd Hotchkiss 37mm and 75mm, and a few outdated pieces employed by the rebels early on), warfare was not as static as it was to become on the Western Front in Europe. Many of the armies were composed mainly of cavalry, and, with the rebels' tendency to flee into the mountains when outnumbered or defeated, mobility was placed at a premium.
Troops of all types were transported by train, when possible, and the railroads played a major role in strategic considerations, forming the major supply routes as well. As a result of this, and of the fact that this war was a Revolution, and highly politicized, most fighting occurred in towns and cities.
As for troop tactics, infantry tended to fight in open order "skirmish" formations - the result of facing effective artillery and small-arms fire. Cavalry was basically a highly mobile form of infantry, although swords were carried by many cavlry units for close action (the lance, oddly enough in a Mexican conflict, was completely absent). Artillery, although capable of indirect fire, was generally not deployed in this role. We do not see much long-term static warfare during this conflict, which results in the lack of such weapons as trench mortars and heavy field artillery, although entrenchments were common for defensive positions, and there were many seiges.
Villa's army gives us an example of how an all-cavalry force (effectively a very large group of bandits) could be transformed into a trained army of all arms. Villa understood the importance of having infantry and artillery in his army, and went about building these arms with the help of professional officers. While never very uniform in appearance, the military discipline among the Villistas was as good or better than among the more "regular" Mexican armies at this time.
Zapata's forces show us similar tendencies: initially, the army was simply a federation of "jefes," each with their personal following. Starting in 1913, however, Zapata began mandating the appointment of corporals and sargeants, and instituting rudimentary military discipline. He also began recruiting among the Federalistas around this time, to find professional military men to train his forces.
Tactically, although very fond of night attacks and the use of "les ruses de guerre," Villa preferred frontal assaults. He would almost always go on the offensive once a battle was joined, and this generally brought him success throughout the early part of the war. He was not incapable of performing flank marches and so on, but neither does he display any great ability in this regard. Zapata is similar in this regard: he was initially a guerilla commander, but as the war progressed, he was forced to transform his army into something capable of fighting offensive battles, which required a somewhat different set of tactics. The frontal assault tactics come from the "hit-and-run" strategy of guerillas - you use these tactics to overwhelm a weak enemy. Zapata, like Villa, learned more about the military art as the Revolution progressed, but was never a notable tactician.
Generally speaking, the Carrancista and Federalista generals showed much less initiative than did those fighting for Zapata or Villa, and their troops were much more likely to be found standing on the defensive. The "Rurales," Mexico's mounted poice, provided a group of experienced veterans that bolstered the government's armies. Many "Yaqui" indians were drafted by all sides in these conflicts. It was not unheard-of for women to act as combatants, although this was much more frequently the case with the Villistas and Zapatistas than it was for more "professional" forces. For all armies, vast hordes of "soldaderas" accompanied their men on the march, if not into battle.
The relationship between Carranza's government and Imperial Germany resulted in a situation that changed the picture. At the two battles of Celaya, in 1915, the Carrancistas started using tactics learned from observers on the Western Front in Europe - trenches, spotlights, barbed wire, and concentrated machinegun and artillery fire. Against this tactical system, the standard frontal assaults of the Villistas were suicidal. After learning some very bloody lessons, Villa started relying more on tactical flanking maneuvers, but by this time his army was close to disintegration.
Given the frequency with which officers and soldiers switched allegience during this war, it is not at all surprising to see that most of the forces used equivalent tactics and equipment, Celaya being the one great exception.
While no doubt covered in much greater detail elsewhere, the tactics of the U.S. forces deserve mention here. As a general rule, U.S. forces conducted themselves in accordance with battle experience gained during the Spanish-American War and in the Phillipines. The use of cavalry as the only sufficiently mobile arm for open campaigning was a feature of Pershing's expedition, although not of the forces who occupied Vera Cruz. The two major innovations introduced by the Americans were the use of aircraft for reconnaisance and extending lines of communication - although not as an effective combat arm - and the use of trucks to provide supply transport. It will be noted that both Pershing and Patton took part in the fruitless search for Villa, gaining valuable combat experience. Otherwise, the U.S. forces fought very much as did the more regular Mexican forces, using open order formations in the face of modern small-arms, and employing cavalry as mobile infantry. It is claimed - although the Canadian forces in Europe make the same claim - that the use of indirect machinegun fire was invented by Americans fighting with the Villistas.
Field organizations during this struggle were fairly normal: typically, infantry were organized into battalions or regiments (the terms are synonymous); cavalry into regiments, troops, and squadrons; and artillery and machineguns into sections, batteries, companies, and regiments. Higher-level formations were somewhat more confusing: typically, several infantry battalions or cavalry regiments were formed into a brigade. With units of mixed arms, the term "column" was typically used for this formation, or for something more closely resembling a division. ("Division" is an abused term during this conflict, because Villa's army was referred to as the "Division of the North," which had been his old command under Huerta). Note that unit strengths varied wildly, so much so that a "brigade" could often be the strength of a typical battalion, and a battalion could have 20 or fewer men in some cases.
Zapata's forces were organized according to he bands of his "jefes," and the rule of thumb was that any jefe who commanded 50 men or more held the rank of "general." After his contact with Villa's forces in Mexico City during 1914, he began creating a more formal military organizational structure, including division of his forces into battalions, regiments, brigades, etc., and also started appointing NCOs acording to military norms.
Villa typically divided his forces into four brigades, although this fluctuated with the size of his force. He used much more regular military structure than Zapata. The same was generally true of the other Northern revolutionaries, many of whom commanded forces partially made up of segments of the government's army which had defected early on, to whom a "regular" military structure was normal.
One point of interest is in army composition: most armies during this conflict were composed of at least 50% cavalry. This is as true of government forces as it is of the Zapatistas and Villistas. Most of the government's armies were composed of an even mix of regular army units and volunteer auxiliary units. The Federalista and Carrancista generals also tended to draft the local peasantry into ad-hoc infantry units when attack threatened, although the quality of these units was no doubt very low.
In order to describe how the different forces were uniformed, we will (somewhat arbitrarily) divide them into the following:
At certain points, the Carrancistas actually formed more than one faction during the fighting, because Obregon commanded a portion of this force. For purposes of describing uniforms, however, this distinction is not important.
A Few Common Items: Perhaps the most distinctive article of clothing for almost all forces in this conflict is the cartridge belt worn over the shoulder, or crossed over the chest. These are not out of place on any figure in this conflict, and the biggest part of "converting" figures from other periods will be carving ordinary belting into cartridge belts. Another common aspect of this struggle - as in other revolutionary conflicts such as the Spanish Civil War - is the use of standards. Infantry and cavalry formations on both sides carried flags - often the Mexican battle flag, but there were some others as well.
Flags: There are a couple of revolutionary flags that I have seen in photographs or museums, and I will describe them here. The first - and by far the coolest - is a Virgin of Guadalupe shown carried as a cavalry standard. This is a swallow-tailed banner that is nailed to a cross-piece on the staff (so that the points of the tail are toward the ground). It shows a picture of the virgin, wearing a crown, surrounded by rays of light. The writing in the borders is not visible in the photograph, but older Mexican standards of this type typically said "Sta. de Guadalupe" on one side, with the stylized "crossed keys" of St. Peter on the other (ed. note: I may well have this wrong, not being Catholic!). The virgin's cloak is of a dark color (blue?), and the rest of her clothing is white. Her head is tilted to her right, in the typical pose of mexican Guadalupes, and her hands folded in prayer. The background is light-colored. This was a Zapatista flag. The second is a red banner with the words "Tierra y Libertad" stitched on it in white. (This latter is a fairly common slogan - first used by the PLM - among the anti-government forces of all sides in this conflict.) A third banner is taken from a mural in Mexico City, depicting the forces of the revolution: A dark orange flag with a black skull-and-crossbones on it. (Arguably, this is even cooler than the Guadalupe banner.) Photographs show a similar flag with a black (or dark) background, with the skull-and-crossbones in white. Other battle-flags were of the traditional Mexican tricolor, either with the eagle-snake-and-cactus motif on them, or with a picture of some particulr leader (the example I've seen depicted Madero, in gold thread).
In coming up with these descriptions, I am mostly relying on a few hundred reprinted photographs obtained from various sources, the biggest of which was a set of books obtained at the Military Museum in Mexico City. While information about the regulation uniforms of the Mexican army for this period certainly exist, these were almost never actually worn, with the exception of a few units participating in the fighting in and around Mexico City, as during the "Decena Tragica." (Again, the only normal exception to this is the artillery, where regulation uniform is more often seen.)
The Villista forces were made up of several styles of civilian clothing, and one of a more military nature.The classification is: (1) "Cowboy" garb; (2) "Peasant" garb; (3) "Indian" garb; (4) "Urban" garb; (5) "Military" garb. The Villistas never placed strong emphasis on military protocol, and their clothing reflected this. The strongest exception to this rule would be the artillery, which tended to be more typically "military" in style because many of it's officers and men were veterans of the professional army.
"Cowboy" Garb: Broad-brimmed cowboy hats, jeans, vests, chaps, cowboy boots (with spurs as appropriate), colored or patterned shirts all describe this basic style. Often you will see a kerchief or string tie. It was not uncommon for the pants and shirt to be replaced with the standard white cotton of the Mexican peasant. This style applies to both infantry and cavalry, although it is more common among the latter. Hats tended to be of a "sombrero" style, but not strictly.
"Peasant" Garb: This is the standard peasant outfit: a sombrero, often with the very tall, pointed crown, white cotton trousers, white cotton pull-over shirt (worn untucked), sandals, shoes, or boots, and poncho or rolled blanket of typical colorful Mexican "weave." This outfit - supplemented with ammunition belts, haversacks, etc. - was the most common one seen among the Villista forces, especially among the infantry and the cavalry. Footgear was fairly common. Some items of this outfit might well be supplemented with khaki-colored military articles captured from the Carrancistas.
"Indian" Garb: Although most of the Indians fighting for Villa actually wore the standard peasant outfit, I have seen a couple of photographs - apparently under combat conditions - of indians dressed in loin-cloth, with their hair worn long under a head-band. The only other article of clothing was the inevitable over-the-shoulder cartridge belt. (This is not a "normal" outfit, but it might have been found occasionally, and I mention it here for completeness' sake.)
"Urban" Garb: Although not common among the Villistas, there is a style of clothing that was found among volunteers who came from more urban areas. This is probably more common among officers, but was not unknown among the rank-and-file. It consists of trousers, vest, and jacket - typically of dark colors, but sometimes white, light grey, or tan - along with a white or light-colored shirt and a neck-tie or string tie. Shoes or boots would be worn, although the shoes were often accompanied by military-style leggings. The headgear would be anything from a bowler to a narrow-brimmed fedora to a broad-brimmed "cowboy hat." Occasionally a sombrero is seen.
"Military" Garb: This outfit was never standard among the Villistas, but you do see photographs in which officers or men are wearing it, typically with some minor variations. It consists of a slouch hat, military blouse and/or tunic, trousers, all in khaki, and military leggings of brown leather. It would be worn with various belting, and often accompanied by a kerchief. This style is seen mostly among the artillery, and is very much like the standard field outfit of the Carrancistas. The blouse was sometimes white. Footgear would generally be shoes, but leggings and shoes can be replaced with boots. (Think of an American trooper of the period, and give him two weeks' leave without a change of clothes.)
The Zapatistas were dressed very much like the Villistas, so I will not go through their garb in detail, except to point on the proprtional differences that are evident. The huge, broad-brimmed sombreros, with tall, pointed crowns were much more common among the Zapatistas, to the point of symbolizing the Zapatista identity. There were fewer of the "Cowboy" and "Urban" styles, and more of the "Peasant". Given that Zapata was very much an agrarian champion, this makes sense. I have never seen pictures of the traditional "Indian" clothing worn by his forces. Again, artillerists (and sometimes infantry or cavalry) could wear the more "Military" style of clothing on occassion.
From the perspective of a wargamer assembling figures, a single army should cover both the Zapatista and Villista forces. Given that these personalities never went head-to-head, it doesn't lead to confusion on the wargames table. I have never seen any specifically Zapatista battle flags, either, so I just use the same ones that I described under the Villista section above.
Those soldiers fighting for Orozco would be almost exactly similar to the Villistas in appearance, except that there tended to be a higher proportion of "military" types. A similar set of troops would be those fighting for Madero early on in the conflict. Carranza, originally a Constitutionalista, would have forces like those of Orozco, until after he took power, at which point his troops are as described below.
The Federalistas were the government forces inherited from the Diaz regime by Madero, and subsequently commanded by Huerta. They begin the war with standard issue uniforms for the Mexican military, and retained a higher level of uniformity than most forces in this conflict (although this is not saying very much!) For wargamer's purposes, a Federalista army is not the same thing as a Carrancista army, so you cannot simply raise one set of "government" troops, although some units will do double duty.
The pre-war infantry uniform, worn by certain units during the Decena Tragica, was a dark blue tunic and trousers with white gaiters, and red trouser-stripes and piping on cuffs and collar. A tapered shako (like the one worn during the 1860s) with brass front-plate and red pom-pom finishes off the ensemble. Belting is black in the photographs I have seen. (A similar uniform with black distinctions would have been worn by the artillery, with green distinctions for the cavalry and light infantry.) This uniform is almost never seen, being the "dress" uniform. The following field uniform seems to have always been worn in preference, except (occasionally) by artillerists.
Most common is the standard field uniform, consisting of white or khaki trousers and tunic and a blue cylindrical kepi (which began to look like an American-Civil-War style kepi after a period in the field). Sometimes there would be red trim on collars and cuffs, although this is not common. Officers wore more elaborate and definitively cylindrical kepis, also blue), shaped like the French in WWI, and tended to have a dark-blue uniform trimmed in metallic colors. Belting consisted of a waist-belt and crossed ammunition bandoliers. A bayonet was typically carried, and a pack, with inverted "U" blanket roll of grey or tan, or Mexican colored weaving. Haversacks and canteens are also seen. If the pack was absent, the blanket was worn as a shoulder-roll. Some photos from early in the conflict show a medium-grey overcoat worn by some troops, making them look very much like early-WWI French infantry. To model these figures, I use Union American Civil War figures, with cross-belts carved into ammunition bandoliers.
As the conflict progressed, you see an increasing incidence of a British-style peaked cap. Initially, this is in dark blue like the kepi, with a black visor and band, but soon you see the color change to khaki, to match the rest of the field clothing. Occasionally, there appear to be figures wearing the khaki uniform and pith helmets, although these may be artillerists acting like infantry.
Officers carried swords and revolvers, and tended to wear a variety of headgear: the cylindrical kepi mentioned above, or a peaked cap in blue or khaki, or a pith helmet. Obviously, this was left more up to individual taste than it was for the enlisted men, and the higher the rank, the more likely it was that the style would be non-standard.
Note that in old black-and-white photographs, khaki tends to photograph as white unless there is a real white in the photo, in which case it gets darker than it should be (in the same way that yellow often photographs black). You have to be careful when going through these old photos!
The original artillery uniform has been described above, as a variation on the same early version of the infantry uniform, but this is not often seen. Two uniforms are most common: one is an exact duplicate of the standard infantry uniforms, either with white or khaki clothing and blue kepi, or khaki uniform and peaked cap. More often, you see artillery crews wearing a khaki uniform with brown belting around the waist, crossed in the back, and falling straight from the shoulder to the waist in front. A pith helmet, also, khaki, completes the outfit. Brown leather gaiters would sometimes be worn. Equipment was much the same as for the infantry.
Machine-gunners were typically uniformed like the artillery.
Cavalry uniforms also resembled those of the infantry, with a few changes. Swords were fairly common, as were revolvers. The cavalry did not wear the peaked cap in any photos that I have seen. With a khaki uniform, they tended to wear a pith helmet, and possibly a brimmed slouch hat. Belting tended to consist of waist-belt, crossed belts in back, and shoulder-to-waist belting in front, with less incidence of the crossed bandoliers phenomenon.
You will frequently see volunteer units dressed in khaki (sometimes white) trousers and jackets, with white shirts, the whole topped off with a straw brimmed hat, typically turned up on one side, with a hat-band. Hats are sometimes khaki slouch hats (like the Carrancista field uniform). These units can be both infantry and cavalry units.
The Rurales were the Mexican "mounties," although they acted a good deal more like bandits than their Canadian bretheren! They wore felt sombreros, generally of a light color (tan or grey), and had matching trousers and short jacket of red-brown, khaki, or white (in descending order of incidence). Shirts were typically white. They tended to have a more uniform appearance than most volunteer units, and in some cases more than the regular Federalista units.
The Carrancistas as described here are those units that fought against the Revolution after Carranza's assumption of power and subsequent falling-out with Villa, Zapata, and other Conventionista generals.
The basic uniform was a khaki tunic and trousers, generally worn with a broad-brimmed hat in the same color. Infantry equipment was the same as for the Federalistas, although it varied widely. Infantry and artillery worn brown leather gaiters (sometimes), and cavalry wore boots. You also see many Carrancista forces wearing a khaki peaked cap (all arms). The kepis and white field uniforms of the Federalistas had largely vanished at this point. Bandoliers are much in evidence, however, as are cartridge waist-belts similar to those worn by American troops. Volunteer units and Rurales dressed just as they had under the Federalistas.
Because this subject is well-documented elsewhere, just a few quick notes: by this point, U.S. Cavalry and Infantry units had switched to the all-khaki uniform first worn during the Spanish-American War. The marines still wore the "bluejacket" uniforms during the action at Vera Cruz.