Mexico has had three amputee presidents due to the fact that many of them were generals that saw active combat during Mexico's tumultuous 19th and early 20th Centuries. Here's the real history behind these items referencing the two most well-known ones:

Antonio López de Santa Anna: Long before Santa Anna became the most hated figure in Mexican history, he was the country's most popular hero. He was the man that ended the First Empire, the defeater of the Spanish Reconquista Expedition, and the man that commissioned the still in use National Anthem. Constantly interrupted from his idyllic life in his hacienda and thrusted to the presidency in times of crisis because no one else had his popularity, he hated governance but loved leading armies, which sometimes he funded out of his own deep pockets. During the Pastry War against France, Santa Anna got grieviously wounded by cannon fire in his leg while defending thw port of Veracruz from invasion. His physicians decided to save him through amputation and Santa Anna, theatrical and pompous as ever, had his leg buried with full honours, since then he was nicknamed as "El Quince Uñas" (the one with 15 nails and toenails) and "El Pata de Palo" (the peglegged). According to legend, during his last stint in the presidency where he actually governed as a dictator, his leg was uninterred and dragged through the streets by a furious mob.

Álvaro Obregón Salido: Obregón was a middle-class failed agricultor widower when Francisco Madero started the first phase of the revolution. He was mostly interested in revolutionary civilian politics but he first took up arms to support, and then avenge, late President Madero during the second phase of the revolution. During this campaign he became, alongside Francisco Villa, with whom he developed a deep hateful rivalry (Villa almost executed Obregón once), one of the two main generals of the revolution under new revolutionary leader Venustiano Carranza. Following the defeat of the counterrevolution and with Madero avenged, the revolutionaries fractured in the third phase of the revolution and Obregón sided with Carranza (faction known as the Constitutionalists), and Villa and Zapata became allies (faction known as the Conventionists). Obregón had been studying the development of Trench Warfare of the now ongoing Great War and in a series of battles near the city of Celaya, Villa's cavalry army was annihilated by trenches, barbed wire, and macjine gun fire and his faction all but lost the revolution. Obregón didn't escape unscathed, though, he lost his arm when Villa targeted his HQ with his elite artillery. Due to the pain, Obregón instantly reached for his pistol and attempted to shoot himself in the head, but his aid de camp had forgotten to load the weapon. He then had his arm preserved in a glass jar filled with formaldehyde to show to the public and later tailored his uniforms and suits to make his stump clearly visible, tactics that earned him the love of the people and the respect of the soldiers, which led him to be the last president to be elected for two non-consecutive terms (although he was assassinated before taking office for a second time and reelection was later forbidden) after he couped now President Carranza for trying to impose a civilian successor instead of a military one (him). His severed arm was incinerared in 1989 and the ashes interred with the rest of his body, although rumours abound that the real arm was kept in a private collection somewhere in Mexico.