In February 1850, San Diego County was officially created but it would be another seven months before California was made a state.

With borders extending to Arizona and Southern Nevada, the new county was as large as twelve east coast states.  Over the next seventy years San Diego County was broken up to form Riverside, Orange, San Bernadino and Imperial counties.

On March 27, 1850, the first county charter was passed and Sidney Livingston was appointed City Marshal of San Diego.  Less than two months later he was released from his duties when, in May 1850, the City of San Diego was officially incorporated.