[4][5] Crocker had one brother[6] and three sisters,[3] one of whom (Lizzie Eldridge) married the prominent judge William Cary Van Fleet in 1887.

[3][10] In 1879 he started work with Sisson, Wallace & Co., beginning a successful business career that lead to directorships of numerous firms and the acquisition of great wealth.

[19] In public appearances, Crocker was greeted by adoring crowds, giving him confidence he would defeat incumbent Mayor Eugene Schmitz of the Union Labor Party.

[20][21] Crocker's popularity was demonstrated in the days before the election, with a parade that attracted thousands[22] and numerous endorsements from union labor officials[23] and local businessmen.

[24] When Schmitz was re-elected, the San Francisco Call blamed the unsuccessful campaign of Democrat Franklin K. Lane for splitting the anti-Schmitz vote.

[25] Following the 1906 San Francisco earthquake, Crocker was named to the Committee of Fifty, a group of prominent citizens formed by Mayor Schmitz to deal with the crisis.