Born August 23, 1869 in San Francisco and, educated in Mission District schools. He began his business career as an office boy in the commission house of Kittle & Co.
In 1900, he formed a partnership with George Hind and engaged in the shipping and commission business.
In 1903, he helped found the Mission Bank, of which he became president. He also served as president of the Mission Savings Bank. He founded the Rolph Shipbuilding Company, and the James Rolph Company.
He was asked to run for mayor in June 1909, but declined, choosing to run in the 1911 election.
For the next 19 years Rolph was "Sunny Jim" to San Franciscans with "There are Smiles That Make You Happy" as his theme song.
Along with his job as mayor and his private shipping interests he also served as director of the Ship Owners & Merchants Tugboat Company, the San Francisco Chamber of Commerce, president of the Merchants' Exchange, and vice-president of the 1915 Panama-Pacific International Exposition.
In November 1930, James Rolph, Jr. won the California gubernatorial election, with his resignation as mayor effective simultaneously with his inauguration as governor, on Tuesday, January 6, 1931.
On November 9, 1933, Brooke Hart, son of a wealthy San Jose merchant was kidnapped. The two men responsible were caught, later forcibly removed from jail and hanged by a vigilante committee in San Jose's St. James Park.
Governor Rolph, by condoning the lynching, was nicknamed "Governor Lynch" and received extremely bad publicity across the nation.
Following this episode, he suffered several heart attacks and died at Riverside Farm, Santa Clara County, on June 2, 1934. Gladys Hansen