Ranald Mackenzie only lived to be 48 years old, and was insane at the end, but he was wounded so many times during his career it's a wonder he lasted that long. Not only was he a tough guy, he was also a smart guy. He graduated from West Point at the top of his class, whereas his contemporary, Armstrong Custer graduated at the bottom of his class a year earlier. Mackenzie and Custer had similar careers, however, Mackenzie didn't get himself surrounded and wiped out.
Ranald went straight from West Point to war. He started out as a 2nd lieutenant, fought in battle after battle, being wounded at least six times. He ended the war as a brevet Major General of Volunteers, which was Congress' way of saying "good job pal, but you're not getting any more money!"
After the Civil War, he stayed in the service and was involved immediately in the Indian Wars, commanding a Buffalo soldier regiment in 1867, and finally taking over the 4th US Cavalry, where he got down to some serious Indian fighting. He was wounded again with an arrow to the leg, and his nickname among the Indians was "Bad Hand", from a wound in the Civil War where he lost a couple of fingers from his right hand. He took the battle to the Comanche's own heartland, defeating them in the Battle of the North Fork along the Red River. Mackenzie's scouts were reportedly cannibals, which caused the surviving Comanches to hide their dead.
Mackenzie led his troops after the Cheyenne in Wyoming Territory and engaged them in a savage battle know as the Dull Knife fight (Dull Knife was a Cheyenne leader). He was a tough guy among tough guys, and on this day again he came out on top, ending the Cheyenne as a fighting force.
By 1884, he was drummed out of the army, his mind already losing it's grip with reality. Some say the cause was a fall from a wagon, but an entire lifetime of combat must take it's toll somewhere. By 1889 he was dead and now resides at Arlington. There are several places in Texas that have his name, and there was even a forward operating base in Iraq named for him. To appreciate what he went through, you can get a taste of it by watching the 1950 John Wayne film, Rio Grande, which is loosely based on Mackenzie's exploits.
The following video is from Rock Island auctioneers who sold a 4th Cavalry Colt
from Mackenzie's outfit