Career
Born in San Jose, California, Sweigert received an Bachelor of Arts from the University of San Francisco in 1921 and an Bachelor of Laws from the University of San Francisco School of Law in 1923. He was in private practice in San Francisco, California from 1923 to 1940, and was a Lecturer at the University of San Francisco School of Law from 1925 to 1932. He was an assistant state attorney general (later chief assistant attorney general) of California from 1940 to 1942, and was then an executive secretary to Governor Earl Warren 1943.
He was a judge on the Municipal Court of San Francisco in 1949, and on the California Superior Court from 1949 to 1959.
Sweigert was confirmed by the United States Senate on September 14, 1959, and received his commission on September 21, 1959. He assumed senior status on November 30, 1973, serving in that capacity until his death.