born Oct. 18, 1801, Arroyo Urquiza, Viceroyalty of the Río de la Plata
died April 11, 1870, Entre Ríos province, Arg.
Argentinian soldier and statesman who helped overthrow Juan Manuel de Rosas .
He became governor of Entre Ríos province in 1841 and allied himself with other provincial leaders to overthrow the dictatorial Rosas in 1852. As provisional dictator, he called a constitutional convention that sanctioned a constitution modeled on that of the U.S. All provinces accepted it, but the province of Buenos Aires, determined to lead the nation, refused to join the new union until 1859. Urquiza stepped down in 1860 and led the Argentinian army in the Paraguayan War . He and his sons were assassinated by a political rival. See also Bartolomé Mitre .