Ralph Hosea Chaplin (1887–1961) was an American writer, artist and labor activist.
 At the age of seven, he saw a worker shot dead during the Pullman Strike in Chicago, Illinois.
 He had moved with his family from Ames, Kansas to Chicago in 1893.
 During a time in Mexico he was influenced by hearing of the execution squads established by Porfirio Díaz, and became a supporter of Emiliano Zapata.
 On his return, he began work in various union positions, most of which were poorly paid.
 Some of Chaplin's early artwork was done for the "International Socialist Review" and other Charles H. Kerr publications.
Juana Belén Gutiérrez de Mendoza (27 January 187513 July 1942) was an anarchist and feminist activist, typographer, journalist and poet born in San Juan del Río, Durango, Mexico.
 While many women contributed in the Mexican Revolution 1910-1920 by fighting alongside their husbands, others wrote against the injustices of the Díaz regime.
 In May 1901 she found an anti-Díaz newspaper called "Vésper".
 She attacked the clergy in Guanajuato and wrote against foreign domination in Mexico.
 She also wrote against the Díaz regime and criticized Díaz for not carrying out the requests and needs of the people.
 As a result, her newspaper was confiscated and she was also put in jail several times by Díaz between 1904 and 1920.
 She established a new newspaper called "El Desmonte" (1900-1919) and continued her writings.
 She encouraged workers and peasants to vote as she wrote “not to integrate power, but to disintegrate it, as a means of forming, not a new oligarchy but of transforming the oligarchies into truly public administrations.”
 She argued that the Mexican Population could not count on the leadership of political parties given that they wanted to obtain office in order to protect their own interests.
 To propagate liberation ideology throughout Mexico, Juana Belén Gutiérrez de Mendoza translated the works of Peter Kropotkin, Mikhail Bakunin, and Pierre Joseph Proudhon to Spanish.
 Even though she was intimidated throughout her life, she continued writing and educating the public on the injustices the different governments brought upon Mexico.
 She is one of the many intellectuals who contributed with her writings to the Mexican Revolution.
Félix Díaz Velasco (17 February 18689 July 1945) was a Mexican politician and general born in Oaxaca, Oaxaca.
 He graduated as an engineer from the Colegio Militar in 1888.
 He was a leading figure in the rebellion against President Francisco I. Madero during the Mexican Revolution.
Emiliano Zapata Salazar (] ; 8 August 1879 – 10 April 1919) was a leading figure in the Mexican Revolution, the main leader of the peasant revolution in the state of Morelos, and the inspiration of the agrarian movement called "Zapatismo".
Manuel San Martin was born in 1881 in Distrito Federal, Mexico.
 A Captain in the Mexican Army and notable figure of the Mexican Revolution.
 He opposed corruption within the high ranks of his command in order to save the lives of prisoners wrongfully set for execution.
 He saved the lives of countless victims of the Mexican Revolution, where more than two (2) million people lost their lives.
 He married Concepcion Espinosa and they had ten children together.
 He died on March 25, 1965, in Distrito Federal, Mexico, at the age of 84.
"La Adelita" is one of the most famous "corridos" (folk songs) of the "Mexican Revolution" (1910-1920) that has been adapted in various forms.
 This particular version of the ballad (which is also shown in the form of a portrait) was inspired by a Durangan woman (whose identity has not been yet established beyond doubt) who joined the Maderista movement (the revolutionary party led by Francisco I. Madero) at an early stage of the Revolution, and supposedly fell in love with Madero, her revolutionary leader.
 Consequently, this popular icon became the source that documented the role of women in the Mexican Revolution, and gradually became synonymous with the term "soldadera" or "female soldier" who became a vital force in the revolutionary war efforts due to their participation in the battles against Mexican government forces."
"Solidarity Forever", written by Ralph Chaplin in 1915, is perhaps the most famous union anthem.
 It is sung to the tune of "John Brown's Body" and "The Battle Hymn of the Republic".
 Although it was written as a song for the Industrial Workers of the World (IWW), other union movements, such as the AFL-CIO, have adopted the song as their own.
 The song has been performed by musicians such as Utah Phillips, Pete Seeger, and was redone by Emcee Lynx and The Nightwatchman.
 It is still commonly sung at union meetings and rallies in the United States, Australia and Canada, and has also been sung at conferences of the Australian Labor Party and the Canadian New Democratic Party.
 This may have also inspired the hymn of the consumer cooperative movement, "The Battle Hymn of Cooperation", which is sung to the same tune.
Soldaderas, often called Adelitas, were women in the military who participated in the conflict of the Mexican Revolution, ranging from commanding officers to combatants to camp followers.
 "In many respects, the Mexican revolution was not only a men's but a women's revolution."
 Although some revolutionary women achieved officer status, coronelas, "there are no reports of a woman achieving the rank of general."
 Since revolutionary armies did not have formal ranks, some women officers were called generala or coronela, even though they commanded relatively few men.
 A number of women took male identities, dressing as men, and being called by the male version of their given name, among them Ángel Jiménez and Amelio Robles.
The Border War, or the Border Campaign, refers to the military engagements which took place in the Mexico-United States border region of North America during the Mexican Revolution.
 The Bandit War in Texas was part of the Border War.
 From the beginning of the Mexican Revolution in 1910, the United States Army was stationed in force along the border and on several occasions fought with Mexican rebels or federals.
 The height of the conflict came in 1916 when revolutionary Pancho Villa attacked the American border town of Columbus, New Mexico.
 In response, the United States Army, under the direction of General John J. Pershing, launched an expedition into northern Mexico, to find and capture Villa.
 Though the operation was successful in finding and engaging the Villista rebels, and in killing Villa's two top lieutenants, the revolutionary himself escaped and the American army returned to the United States in January 1917.
 Conflict at the border continued however and the United States launched several more smaller operations into Mexican territory until after the American victory in the Battle of Ambos Nogales, leading to the establishment of a permanent border wall.
 Conflict was not only subject to Villistas and Americans; "Maderistas", "Carrancistas", "Constitutionalistas" and Germans also engaged in battle with American forces during this period.
Emiliano Zapata was a leading figure in the Mexican Revolution

Question: When was the leading figure in the Mexican Revolution which Ralph Chaplin was his suppoter born 
Answer: 8 August 1879