Emiliano Zangora.
Pedro Hermión, the President of the United States of Mexico, was shot and instantly killed on 19 June 1851 immediately after giving a speech to the Mexican Congress. His assassin was a disgruntled former member of the Presidential guard named Emiliano Zangora.
Hermión's popularity had suffered a severe downturn in the wake of the Battle of Williams Pass of November 1850 to April 1851. Two Mexican armies totalling 97,000 men had suffered 66,000 fatalities in the bitter conditions of Williams Pass, and there was a growing fear that the U.S.M. was on the verge of losing the Rocky Mountain War. All of Hermión's efforts to reassure the nation were unsuccessful. There were several attempts made on his life in the spring of 1851, and he was unable to leave the Presidential Palace without a large force of armed guards.
On 19 June Hermión made a special address to the Congress in which he defended his prosecution of the war, denounced the anti-war opposition, and vowed to defeat the Confederation of North America and personally dictate peace terms to Governor-General Henry Gilpin. The special address was a great success, and half the members of Congress rose to give Hermión a standing ovation afterwards.
President Pedro Hermión.
A member of Hermión's audience occupying a place in the gallery behind him was Zangora, a former member of the Presidential guard who had been refused promotion, and who blamed Hermión and vowed to avenge himself. After the conclusion of the speech, as Hermión was bowing to the applauding members of Congress, Zangora shot him in the back of the head, killing him instantly. Zangora then attempted to flee the hall, shouting "Viva Huddleston y Paz", but before he could escape he was shot dead by the Congressional guard.
At first it was assumed that former President Miguel Huddleston had been behind the assassination. The Congress established the Fuentes Commission to investigate the assassination, and in its Final Report the Commission cleared Huddleston of any wrongdoing, concluding that Zangora had acted alone. Despite this, Sobel states that there are still people who believe that former President Miguel Huddleston arranged the assassination, while another group believes that Governor-General Gilpin was behind Hermión's death.
Sobel's sources for Zangora's assassination of President Hermión are the Commission to Inquire into the Assassination of President Pedro Hermión: Final Report (Mexico City, 1852); Joan Kahn's The Unknown History of the Hermión Assassination: The Gilpin Connection (New York, 1968); and Samuel Menzer's The Huddleston Conspiracy: The Brown Menace of 1851 (London, 1970).