Under the terms of the 1857 Constitution, the President of the Supreme Court of Justice became interim President of Mexico until a new election could be held. Juárez was acknowledged as president by liberals on 15 January 1858 and assumed leadership of the Liberal side of the civil war known as the War of the Reform ("Guerra de Reforma"), (1858–60). During this war, Mexico had rival governments of the liberals under Juárez, in a constitutional succession, and the rebellious conservatives under Félix María Zuloaga.