Ogazón participated on the liberal side in the
Reform War and distinguished himself in the Battle of Guadalajara, defeating the conservative general Severo Castillo. At the behest of President
Benito Juárez, Ogazón became the interim governor of the state of Jalisco in 1858, until the arrival of the conservatives. In 1859, Degollado appointed him Brigadier General of the First Division of Jalisco, and in 1860, he was named commander of the Central Division. At the end of the Reform War, Pedro Ogazón was elected governor, a position he held until 1862. During these two years, he left his cousin and general secretary Ignacio Vallarta in charge while he fought Manuel Lozada, "the Tiger of Álica," on multiple occasions. His mission was interrupted during the
Second French Intervention in Mexico, leading him to sign the Pochotitlán treaties with Lozada. He defended the port of Mazatlán in the eponymous Battle of Mazatlán in 1864 after returning from San Francisco with weapons for the defense. During the French intervention, he traveled constantly between San Francisco and New York, acting as an agent to secure financial support and armaments. From May 1866, he returned to Mexico and served under General Silvestre Aranda, participating in the Siege of Querétaro in 1867. With the restored Republic, he became a magistrate of the
Supreme Court of Justice of the Nation from 1868 to 1874. == Tuxtepec Rebellion ==