Very little is known about "Mary’s Tap" or "Mary's Tavern" as a gay bar. We know that it had previously been called "Old Mill Inn", and both had gay customers as a large part of its clientele. The term "gay-for-pay" is sometimes used in reference to such early 'gay' bars. Patrons remember a more protective police presence than at other bars.

The location is reknowned today as "the Black Nite". In 1960, Wally Whetham had reopened what had been known as "Mary’s Tavern" as "the Black Nite" to celebrate its gay customers. The "Black Nite" is well known now because on a Saturday night, August 5, 1961, Black Nite was the scene of a sensational bar brawl. When a serviceman was thrown out of the bar, he returned with friends, looking for a fight. They found 74 customers ready and willing to defend their turf. "My boyfriend was a bouncer," said Josie Carter, "and we did not run from a fight. We didn’t start anything, but we sure as hell finished it. I could fight an Army off in a bathrobe."

That 'bar brawl' is documented in this Event page. On August 5, 2021, the Black Nite was commemorated by the County Board, County Executive, City Council, Mayor and Governor at a press conference on the anniversary of the Brawl on the former site of the building. In 2022 the brawl was recognized as an historical event and the site as a landmark by the Milwaukee County Landmarks Committee.

In 2023 an official state Historical Marker was created by the Wisconsin Historical Society as the state's first LGBTQ-related marker. The marker was erected on the 63rd anniversary of the brawl (August 5, 2024) across the street from the site. (The actual site is now partly in the footprint of the St. Paul Avenue, and the land is slated for construction of a new restaurant- and thus the location across the street was deemed a more suitable location for the time being.)

Through it all, "Mary's Tavern" was not forgotten however. According to a news article: "On July 22 1960, the Milwaukee Police Department voted against giving Mary Wathen a license to operate the Sunflower Inn (1806 W St Paul Ave.,) when "Dirty Helen" Cromwell retired due to financial difficulties. Wathen had reluctantly managed "Mary's," one of the city's first gay-for-pay bars at 400 N Plankinton Ave, from 1959-1960. Police Chief Johnson advised against licensing as Mary's had attracted "undesirable elements - even more undesirable than Dirty Helen herself."