In 1910 José Santos Zelaya from the Liberal Party stepped down from government. In 1925 his continuing opposition to Conservative control of the Nicaraguan government forced him to flee to Costa Rica, where he continued to build support for a return of the Liberals to power. Moncada was one of the leaders, together with Juan Bautista Sacasa and Augusto César Sandino.
Moncada and Sacasa made peace, but Sandino refused and continued the fight and waged a guerrilla war against the U.S. Marines. But in 1928, after elections supervised by the Marines, Díaz was replaced as president by Moncada. Moncada's children included the late Óscar Moncada, who served as the President of the National Assembly of Nicaragua from 1999 until 2001.