Luis Munoz Marin was the first governor of Puerto Rico after the island was given the right to elect its own governor. He was re-elected three times. Son of a Puerto Rican publisher and patriot, he was a long-time activist in island affairs. Early in his career he advocated Puerto Rican independence from the United States and was an avowed socialist. He returned to the island from the mainland in 1926 to edit his father's paper. Munoz was president of the Puerto Rico senate from 1940-1948 when his party lost the election. In his first term as governor, Munoz worked to change the island's status. On July 25, 1952, the new Commonwealth Constitution went into effect. Munoz refused to run again for governor in 1964 and he returned to the senate.