AT: "xx" Madison Square Garden was an arena in New York City used for boxing, among other things.
In 1930, a boxing event took place there with Mike Mason vs. Kid McCook as the main event over ten rounds, then Manuel Prado vs. Will Bailey over six rounds. Preliminary fights were Gus Lloyd vs. Killer Kidd, Ricky Mason vs. Buddy Sencio, and Charley Mulaney vs. Gus Barnes. General admission cost US$1.25. (TOS: "The City on the Edge of Forever")
In an alternate timeline, Madison Square Garden hosted Adolf Hitler after the city was captured by German forces. (ENT: "Storm Front, Part II")
Literature
In The Big Good-Bye, according to the narrator, the desk lieutenant showed little interest in his fellow officer, Jim Tierney, being in the room. As far as the lieutenant was concerned, Tierney might well have been in Madison Square as in front of his desk for all the attention he would give to him (TNG: "The Big Goodbye")