These were the men who made up the bulk of the regiment, and gave it its peculiar character. They came from the Four Territories which yet remained within the boundaries of the United States; that is, from the lands that have been most recently won over to white civilization, and in which the conditions of life are nearest those that obtained on the frontier when there still was a frontier. They were a splendid set of men, these Southwesterners—tall and sinewy, with resolute, weather-beaten faces, and eyes that looked a man straight in the face without flinching. They included in their ranks men of every occupation; but the three types were those of the cow-boy, the hunter, and the mining prospector—the man who wandered hither and thither, killing game for a living, and spending his life in the quest for metal wealth.
In all the world there could be no better material for soldiers than that afforded by these grim hunters of the mountains, these wild rough riders of the plains. They were accustomed to handling wild and savage horses; they were accustomed to following the chase with the rifle, both for sport and as a means of livelihood. Varied though their occupations had been, almost all had, at one time or another, herded cattle and hunted big game. They were hardened to life in the open, and to shifting for themselves under adverse circumstances. They were used, for all their lawless freedom, to the rough discipline of the round-up and the mining company. Some of them came from the small frontier towns; but most were from the wilderness, having left their lonely hunters’ cabins and shifting cow-camps to seek new and more stirring adventures beyond the sea.
The Rough Riders by Theodore Roosevelt. More images here.