In 1932, Knowland went to Washington and persuaded President Herbert Hoover and the Reconstruction Finance Corporation to advance $62 million for the completion of the San Francisco–Oakland Bay Bridge. He created, with Bruno Albert Forsterer and Joseph Blum, the Franklin Investment Company in 1936 (later the Franklin Credit Union). In 1937, he attained the status of 33rd Degree Mason, Ancient Accepted Scottish Rite. Knowland was a member of the Finance Committee of the Golden Gate International Exposition of 1939-1940. In 1941, he authored "California: A Landmark History". He was the political mentor of Earl Warren; from assistant Oakland City Attorney to Chief Justice of the United States Supreme Court.