[citation needed] The top floor initially housed the headquarters of the notorious Abe Ruef, a local political figure at the time.

In 1949 or 1950, the nightclub hungry i, which would become very influential in the history of stand-up comedy in the US, was opened as an 83-seat venue in the Sentinel Building's basement by Eric Nord, who sold it to Enrico Banducci in 1951.

[4] After operating it as a venue for folk singers including Stan Wilson, Banducci began hiring comedians in 1953 with Mort Sahl, encouraging them to express themselves freely.

[5][4] In 1958, when the Sentinel Building's state had deteriorated and it was threatened with destruction, it was bought by Dutch-born investor Rob Moor and his wife Nella, who renovated it, renamed it to "Columbus Tower", and sold it one and a half years later at a profit to The Kingston Trio.

[10] Columbus Tower can be seen in Star Trek IV: The Voyage Home when James T. Kirk and his crew are first walking through San Francisco after arriving in 1986.