Born in Caracas in 1783, Simón Bolivar was a Venezuelan military and political leader who led several countries in Central and South America to independence from Spanish colonial rule during his lifetime. Following initial military successes against the forces of imperial Spain, he strove to establish a union of independent nations (consisting of present-day Colombia, Venezuela, Ecuador and Panama) that was called Gran Colombia. This was realized on 17 December 1819 and Bolivar served as president until 27 April 1830. The new republic of Gran Colombia was, however, hampered by internal division and dissent. Following a series of uprisings, Bolivar called a constitutional convention in April 1828 in which he sought to establish a federation of states on the model of the United States of America. Held at Ocaña from 9 April to 10 June, the convention, however, failed in producing a new constitution. Consequently, Bolivar proclaimed himself dictator on 27 August 1828 as a temporary measure to try to preserve the union of Gran Colombia. Political uprisings continued to destabilize the country for the next two years, and an attempt to assassinate Bolivar failed on 25 September 1828. Finally, in April 1830, Bolivar resigned the presidency and planned to seek exile in Europe. On 17 December 1830, however, he died from tuberculosis in Santa Marta, Colombia.