Pancho Villa in the context of "Gildardo Magaña"

The Liberation Army of the South (Spanish: Ejército Libertador del Sur, ELS) was a guerrilla force led for most of its existence by Emiliano Zapata that took part in the Mexican Revolution from 1911 to 1920. During that time, the Zapatistas fought against the national governments of Porfirio Díaz, Francisco Madero, Victoriano Huerta, and Venustiano Carranza. Their goal was rural land reform, specifically reclaiming communal lands stolen by hacendados in the period before the revolution. Although rarely active outside their base in Morelos, they allied with Pancho Villa to support the Conventionists against the Carrancistas. After Villa's defeat, the Zapatistas remained in open rebellion. It was only after Zapata's 1919 assassination and the overthrow of the Carranza government that Zapata's successor, Gildardo Magaña, negotiated peace with President Álvaro Obregón.

The Constitutionalists (Spanish: Constitucionalistas) were a faction in the Mexican Revolution (1910–1920). They were formed in 1914 as a response to the assassination of Francisco Madero and Victoriano Huerta's coup d'etat. Also known as Carrancistas, taking that name from their leader, Venustiano Carranza the governor of Coahuila. The Constitutionalists played the leading role in defeating the Mexican Federal Army on the battlefield. Carranza, a centrist liberal attracted Mexicans across various political ideologies to the Constitutionalist cause. Constitutionalists consisted of mainly middle-class urbanites, liberals, and intellectuals who desired a democratic constitution under the guidelines "Mexico for Mexicans" and Mexican nationalism. Their support for democracy in Mexico caught the attention of the United States, who aided their cause. In 1914, the United States occupied Mexico's largest port in Veracruz in an attempt to starve Huerta's government of customs revenue. They crafted and enforced the Mexican Constitution of 1917 which remains in force today. Following the defeat of General Huerta, the Constitutionalists outmaneuvered their former revolutionary allies Emiliano Zapata and Pancho Villa becoming the victorious faction of the Mexican Revolution. However the Constitutionalists were divided amongst themselves and Carranza was assassinated in 1920. He was succeeded by General Álvaro Obregón who began enforcing the 1917 constitution and calming revolutionary tensions. His assassination and the subsequent power vacuum this created spurred his successor, Plutarco Elías Calles to create the National Revolutionary Party (PNR) which would hold uninterrupted political power in Mexico until 2000.

The United States involvement in the Mexican Revolution was varied and seemingly contradictory, first supporting and then repudiating Mexican regimes during the period 1910–1920. For both economic and political reasons, the U.S. government generally supported those who occupied the seats of power, but could withhold official recognition. The U.S. supported the regime of Porfirio Díaz (1876–1880; 1884–1911) after initially withholding recognition since he came to power by coup. In 1909, Díaz and U.S. President Taft met in Ciudad Juárez, across the border from El Paso, Texas. Prior to Woodrow Wilson's inauguration on March 4, 1913, the U.S. Government focused on just warning the Mexican military that decisive action from the U.S. military would take place if lives and property of U.S. nationals living in the country were endangered. President William Howard Taft sent more troops to the US-Mexico border but did not allow them to intervene directly in the conflict, a move which Congress opposed. Twice during the Revolution, the U.S. sent troops into Mexico, to occupy Veracruz in 1914 and to northern Mexico in 1916 in a failed attempt to capture Pancho Villa. U.S. foreign policy toward Latin America was to assume the region was the sphere of influence of the U.S., articulated in the Monroe Doctrine. However the U.S. role in the Mexican Revolution has been exaggerated. It did not directly intervene in the Mexican Revolution in a sustained manner.

During Díaz's long rule, he implemented policies aimed at modernization and economic development, inviting foreign entrepreneurs to invest in Mexico. The regime passed laws favorable to investors. American business interests invested large amounts of capital, particularly along the U.S.-Mexico border, during the decades of Díaz's rule. There was close economic cooperation between the two governments, which was predicated on Diaz's cooperation with US investors. In 1908 Díaz stated he would not run for re-election in 1910; the statement gave rise to politicking of potential candidates. Díaz reversed himself, ran for re-election, and jailed the leading opposition candidate, Francisco I. Madero. Madero escaped Mexico and took refuge in San Antonio, Texas, and called for nullification of the 1910 elections, declared himself as provisional president, and asked for support from the Mexican people. His Plan of San Luis Potosí sparked revolutionary uprisings, particularly in Mexico's north. The U.S. stayed out of the unfolding events until March 6, 1911, when President William Howard Taft mobilized forces on the U.S.-Mexico border. "In effect this was an intervention in Mexican politics, and to Mexicans it meant the United States had condemned Díaz."

The Pancho Villa Expedition, now known officially in the United States as the Mexican Expedition but originally referred to as the "Punitive Expedition, US Army," was a military operation conducted by the United States Army against the paramilitary forces of Mexican revolutionary Francisco "Pancho" Villa from March 14, 1916, to February 7, 1917, during the Mexican Revolution of 1910–1920.

The expedition was launched in retaliation for Villa's attack on the town of Columbus, New Mexico, an incident of the larger Mexican Border War. The declared objective of the expedition by the administration of US President Woodrow Wilson was the capture of Villa. Despite locating and defeating the main body of Villa's command who were responsible for the Columbus raid, US forces were unable to achieve Wilson's stated main objective of preventing Villa's escape.

José Venustiano Carranza de la Garza (Spanish pronunciation: [benusˈtjano kaˈransa ðe la ˈɣaɾsa]; 29 December 1859 – 21 May 1920), known as Venustiano Carranza, was a Mexican land owner, revolutionary, and politician who served as the 44th President of Mexico from 1917 until his assassination in 1920, during the Mexican Revolution. He was previously Mexico's de facto head of state as Primer Jefe (Spanish: "First Chief") of the Constitutionalist faction from 1914 to 1917, and previously served as a senator and governor for Coahuila. He played the leading role in drafting the Constitution of 1917 and maintained Mexican neutrality in World War I.

Born in Coahuila to a prominent landowning family, he served as a senator for his state during the Porfiriato, appointed by President and dictator Porfirio Díaz. After becoming alienated from Díaz, he supported the Liberal Francisco Madero's challenge to Díaz during the 1910 presidential election. Madero was defeated in a sham election and imprisoned. Madero ordered an overthrow of the government, sparking the Mexican Revolution, and Díaz resigned in May 1911. As president, Madero appointed Carranza as the governor of Coahuila. When Madero was murdered during the counter-revolutionary Ten Tragic Days coup in February 1913, Carranza drew up the Plan of Guadalupe, a political strategy to oust Madero's usurper, General Victoriano Huerta. Carranza organized militias loyal to his state and allied northern states in Mexico into a professional army, the Constitutional Army, to oppose Huerta. The Constitutionalists defeated Huerta's Federal Army and Huerta was ousted in July 1914. Carranza did not assume the title of provisional president of Mexico, as called for in his Plan of Guadalupe, since it would have prevented his running for constitutional president once elections were held. Furthermore his government in this period was in a pre-constitutional, extralegal state, to which both his best generals, Álvaro Obregón and Pancho Villa, objected to Carranza's seizure of the national presidency.

The Constitutional Army (Spanish: Ejército constitucional), also known as the Constitutionalist Army (Spanish: Ejército constitucionalista), was the army that fought against the Federal Army, and later, against the Villistas and Zapatistas during the Mexican Revolution. It was formed in March 1913 by Venustiano Carranza, so-called "First-Chief" of the army, as a response to the murder of President Francisco I. Madero and Vice President José María Pino Suárez by Victoriano Huerta during La Decena Trágica (Ten Tragic Days) of 1913, and the resulting usurpation of presidential power by Huerta.

Carranza had a few military forces on which he could rely for loyalty. He had the theoretical support of Pancho Villa and Emiliano Zapata, but they soon turned against the Constitutionalists after Huerta's defeat in 1914.

Álvaro Obregón Salido (Spanish pronunciation: [ˈalβaɾo oβɾeˈɣon]; 19 February 1880 – 17 July 1928) was a Mexican general, inventor and politician who served as the 46th President of Mexico from 1920 to 1924. Obregón was re-elected to the presidency in 1928 but was assassinated before he could take office.

Born in Navojoa, Sonora, Obregón joined the Revolution after the February 1913 coup d'état that brought General Victoriano Huerta to the presidency. Obregón supported Sonora's decision to follow Governor Venustiano Carranza as leader of the northern revolutionary coalition, the Constitutionalist Army, against the Huerta regime. Obregón quickly became the Constitutionalist Army's most prominent general, along with Pancho Villa. Carranza appointed Obregón commander of the revolutionary forces in northwestern Mexico. The Constitutionalists defeated Huerta in July 1914, and the Federal Army dissolved in August. In 1915, the revolution entered a new phase of civil war between the Conventionists led by Emiliano Zapata and Villa versus Obregón and Carranza. Obregón was made leader of the Constitutionalist army and defeated Villa, but lost his right arm. In 1917, the Constitution of Mexico went into effect and the Conventionists forces were quickly getting defeated by Obregón and the Constitutionalist Army. Carranza stepped down from the presidency and designated Ignacio Bonillas to succeed him. Obregón and other Sonoran generals Plutarco Elías Calles and Adolfo de la Huerta ousted Bonillas and Carranza under the Plan of Agua Prieta. Obregón was elected to the presidency in 1920 with overwhelming popular support.

The Conventionists were a faction led by Pancho Villa and Emiliano Zapata which grew in opposition to the Constitutionalists of Venustiano Carranza and Álvaro Obregón during the Mexican Revolution. It was named for the Convention of Aguascalientes of October to November 1914.