The Broadway Saloon, located on the east side of Broadway between 5th and 6th Streets, was established sometime around 1869 by Peter Backes, proprietor. Backes had immigrated to Oakland from Prussia, Germany.
It doesn't appear to have been around very long; by 1872, there's no mention of the Broadway Saloon, and Backes was proprietor of Zimmerman's Gardens, at the corner of 2nd Street and Harrison.