The Reform War, or War of Reform (), also known as the Three Years' War (), was a civil war in Mexico lasting from January 11, 1858 to January 11, 1861, fought between liberals and conservatives, over the promulgation of Constitution of 1857, which had been drafted and published under the presidency of Ignacio Comonfort. The constitution had codified a liberal program intended to limit the political, economic, and cultural power of the Catholic Church; separate church and state; reduce the power of the Mexican Army by elimination of the fuero; strengthen the secular state through public education; and economically develop the nation. The constitution had been promulgated on February 5, 1857 with the intention of coming into power on September 16, only to be confronted with extreme opposition from Conservatives and the Catholic Church over its anti-clerical provisions, most notably the Lerdo law, which forced the sale of most of the Church's rural properties. The measure was not exclusively aimed at the Catholic Church, but also Mexico's indigenous peoples, which were forced to sell sizeable portions of their communal lands. Controversy was further inflamed when the Catholic Church decreed excommunication to civil servants who took a government mandated oath upholding the new constitution, which left Catholic civil servants with the choice of keeping their jobs or being excommunicated. As opposition to the constitution escalated, President Comonfort, a known moderate, joined conservative Félix Zuloaga's Plan of Tacubaya which amounted to a self-coup on December 17, 1857. The Constitutional Congress was closed, the constitution was nullified, and Comonfort gained emergency powers as President. Comonfort, hoping to establish a more moderate government however, found himself triggering a civil war and began to back away from Zuloaga. On January 11, 1858, Comonfort resigned and was constitutionally succeeded by president of the Supreme Court, Benito Juárez. Mexican states subsequently chose to side with either the Mexico City based government of Zuloaga or that of Juárez which established itself at the strategic port of Veracruz. The first year of the war was marked by repeated conservative victories, but the liberals remained entrenched in the nation's coastal regions, including their capital at Veracruz giving them access to vital customs revenue. Both governments attained international recognition, the Liberals by the United States, and the Conservatives by France, Great Britain, and Spain. Liberals negotiated the McLane–Ocampo Treaty with the United States in 1859. If ratified the treaty would