Mona Sargeant opened the club in 1936, the same year Finocchio's moved to its Broadway location. While Finocchio's featured male performers in female roles, Mona's was a gathering place for women who loved women -- a distinction that mattered in an era when both venues operated in the legal and social margins. The bar drew lesbians from across the Bay Area and became known for its welcoming atmosphere and its female wait staff who dressed in masculine attire, an act of gender nonconformity that was itself a statement in 1930s America.

Operating an openly lesbian bar in the 1930s and 1940s required navigating both hostile law enforcement and a social climate that treated homosexuality as deviance. Mona's survived by drawing tourists as well as regulars -- straight visitors came to see what they considered exotic, and their presence provided economic stability and a degree of protection from raids. The bar's location on Broadway, San Francisco's entertainment strip, placed it alongside burlesque houses and nightclubs where transgressive behavior was tolerated as long as it drew paying customers.

Mona's 440 Club drew lesbian clientele into the 1950s before closing. Its significance lies not in longevity but in precedence: it was the first, in a city that would eventually become the most important center of LGBTQ culture in the United States. The bar predated the Stonewall riots by more than three decades, operating in an era when the idea of gay rights as a political movement did not yet exist. What did exist was a need for community, and Mona's provided a room where that need could be met.