A Pulitzer Prize-winning historian and scholar, he is best known for his biography of Louisiana politician Huey Long. He also published Lincoln and His Generals, a study of the Civil War.
He received his Ph.D. from the University of Wisconsin-Madison in 1937.
He was a history professor at Louisiana State University in Baton Rouge for thirty-eight years.
He married his second wife, Estelle Skolfield, in 1952. From his first marriage, he had a child named Mai Frances.
His biography of Huey Long received both the Pulitzer Prize and the National Book Award in 1970.