Green’s Dictionary of Slang

(US black) a leather coat.

1964		R. Abrahams Deep Down In The Jungle 38: He had on a one-button roll, a two-button satch. / You know, one of them boolhipper coats with a belt at the back.
1970		Major Dict. of Afro-Amer. Sl.
1993–2002		Probert Encyc. 🌐 Boolhipper is Black-American slang for ‘black leather coat.’.