 In 1828, he participated of the Constitutional Convention as a deputy for "Santa Bárbara de Casablanca" (1828-1829).During that period, President Francisco Ramón Vicuña appointed him as Secretary of War and Navy.Muñoz fought in the Chilean Civil War of 1829, and after the final defeat of the Liberals at the Battle of Lircay, he was exiled to the town of Huasco in 1833, where he died at the age of 56.