During the Mexican Revolution, two leaders stand out as carrying out immediate land reform without formal state intervention, Emiliano Zapata in the state of Morelos and Pancho Villa in northern Mexico. Although the political program of wealthy northern landowner Francisco I. Madero, the Plan of San Luis Potosí, promised the return of village lands unlawfully confiscated by large estate owners, when the Díaz regime fell and Madero was elected president of Mexico, he took little action on land reform. Zapata led peasants in the central state of Morelos, who divided up large sugar haciendas into plots for subsistence agriculture; in northern Mexico, Zapata and others in Morelos drafted the Plan of Ayala, which called for land reform and put the region in rebellion against the government. Unlike many other revolutionary plans, Zapata's was actually implemented, with villagers in areas under his forces control regaining village lands, but also seizing lands of sugar plantations and dividing them. The seizing of sugar plantations and distribution to peasants for small-scale cultivation was the only significant land reform during the Revolution. They remained in opposition to the government in its subsequent forms under reactionary general Victoriano Huerta and then Constitutionalist leader Venustiano Carranza. Peasants sought land of their own to pursue subsistence agriculture, not the continuation of commercial sugar cultivation. Although Carranza's government after 1915 fought a bloody war against Zapatista forces and Zapata was assassinated by an agent of Carranza's in 1919, land reform there could not be reversed. When Alvaro Obregón became president in 1920, he recognized the land reform in Morelos and Zapatistas were given control of Morelos. The situation in northern Mexico was different from the Zapatista area of central Mexico, with few subsistence peasants, a tradition of military colonies to fight indigenous groups such as the Apaches, the development of large cattle haciendas and small ranchos. During the Porfiriato, the central Mexican state gained more control over the region, and hacienda owners who had previously not encroached on small holders' lands or limited access to large expanses of public lands began consolidating their holdings at the expense of small holders. The Mexican government contracted with private companies to survey the "empty lands," (tierras baldíos) and those companies gained a third of all land they surveyed. The rest of these lands were bought by wealthy landowners. Most important was the Terrazas-Creel family, who already owned vast estates and wielded tremendous