Jack “Coffee” Hayes was one of the toughest men ever in my book. They named a county after him here in Texas, and Hayes founded the City of Oakland California when he went there after hearing of the gold rush.
Jack Hayes is one of only 30 Texas Rangers in the Texas Ranger Hall of Fame. Definitely more a bad-ass than most on this list.
Another good choice. This author mixes "tough" with pathalogical and sociopath, IMO, regarding JW Hardin. Hardin hated Blacks, carpetbaggers and anyone associated with Texas/Federal government after the war. He killed with glee. There's one story (perhaps apocryphal) about him shooting a sleeping man in Abilene, KS because he was snoring. That's not tough, that's sociopathic...