Green’s Dictionary of Slang

1. a cowboy.

[1880		Bolivar Bull. (TN) 30 Dec. 3/1: [headline] Mr Rawhide Cowboy.
1883		River Press (Fort Benton, MT) 3 Oct. 2/2: [headline] A Duel with Revolvers Between a ‘Texas Rawhide’ and a Montana Cowboy.
1908		Pacific Monthly Feb. 155: I was first, as old rawhiders all confessed [DA].
1939		Abbott & Smith We Pointed them North (2003) 137: Rawhides.2 [note] 2 Derisive Northern name for Texas cowhands. It referred to the Texans’ habit of mending whatever broke down or fell apart on the trail, from a bridle to a wagon tongue, by tying it up with strips of rawhide.

2. a hard worker; a hard taskmaster.

1931		Irwin Amer. Tramp and Und. Sl. 155: RAWHIDER.–A hard worker; a severe taskmaster, one who ‘rawhides’ the workers under his charge.
1962		Ragen & Finston World’s Toughest Prison 815: rawhider – A hard worker; a severe taskmaker.