In 1905, Overton married the former Ada Ruth Dismukes of Natchitoches. They had three daughters, Katharine (1910–1988), Ruth (1912–1973), and Mary Elizabeth (1916–1988), and a son, John H. Overton Jr. (1914–1946).
Career
Overton was admitted to the Louisiana bar in 1898. He established a law practice with four partners in Alexandria and was the city attorney as well. He was a member of the LSU Board of Supervisors.
Overton became a staunch supporter of Huey Long and served as Long's counsel in the impeachment proceedings against the governor in the spring of 1929.
I've supported every governor that has been elected in Louisiana for twenty-five years, all on promises that they have made to the people. Not one of them has been able or, if able, willing to carry out what was expected of him. The present governor is throwing out of office the clique that all other governors promised to throw out. He is backed to the wall in his efforts to redeem his campaign pledges.[2]
In 1932, Overton unseated the two-term US Senator Edwin S. Broussard, of New Iberia, for the Democratic nomination, then equivalent to election in Louisiana. Overton was warmly endorsed by Long, who then became his Senate colleague. Six years earlier, Long had helped Broussard turn back a challenge from a conservative former governor, Jared Y. Sanders Sr., but the two had long since parted political alliances. In his autobiography, Every Man a King, Long notes that Overton won all sixty-four parishes against Broussard, including the incumbent's own Iberia Parish. Long said that Overton had "always been very kind to me. [He] let me speak in his meetings every time he ran for the Senate."[3]
Despite his lopsided loss, Broussard alleged fraud and voter irregularities. A Senate investigating committee held months of hearings beginning in February 1933, but Overton was nevertheless seated without opposition on March 4, the first day of the congressional session. As a senator, Overton generally voted with the Conservative Coalition of Midwestern Republicans and Southern Democrats, much like Broussard.[citation needed]
Overton was re-elected in 1938 and 1944, as has been traditional with incumbent Democratic senators in Louisiana. His committee memberships included Appropriations, Manufactures, Commerce, and Irrigation and Reclamation. His chief area of interest was in flood control and river and harbor development.
Overton attempted to withdraw from re-election race in 1944. However, his Louisiana colleague, Allen J. Ellender, circulated a letter urging him to run. The letter was signed by all of the Senate Democrats.
