Green’s Dictionary of Slang

(US gay) a homosexual male, esp. effeminate and young; a young homosexual woman, esp. boyish.

1935		L.A. Times 24 Mar. II 1/7: CAMPER: A chorus boy, especially of the effeminate type; used generally in a derogatory sense.
1972		B. Rodgers Queens’ Vernacular.
1989–2003		R.O. Scott Gay Sl. Dict. 🌐 baby butch: 1. [kwn NYC, les sl, mid-late ’60s] young boyish, adolescent, teenage lesbian. Synonyms: [late 60s] camper.
2003		K. Cage Gayle 61/1: camper n. gay man.