Green’s Dictionary of Slang

(US Und.) a prison.

1944		P. Kendall Dict. Service Sl. n.p.: cross bar hotel . . . the guardhouse.
1987		‘Joe Bob Briggs’ Joe Bob Goes to the Drive-In 32: Butch said he could keep me out of the Crossbar Hotel for a while if I would send him another hundred.
1992		Bentley & Corbett Prison Sl. 3: Crossbar Hotel A humorous name for prison or jail. The name comes from the presence of steel bars in prison cells. (Archaic: jug, canister).
2000		Other Side of the Wall: Prisoner’s Dict. July 🌐 Cross Bar Hilton: Prison (archaic).