In 1888, while serving as Yavapai County judge, Bucky O,Neil was elected the sheriff, running on the Republican Ticket.
The most famous incident in O'Neill's lawman career happened on March 20, 1889. 4 masked men robbed the Atlantic and Pacific passenger train, in Diablo Canyon. A four man posse, made up of Bucky O'Neill, Jim Black, Carl Holton, and Ed St. Clair, was soon formed and they took off after robbers. On March 21, O'Neill and his posse caught up with the robbers. After exchanging rifle shots, the posse captured the 4 men. During the fight, no men were injured, but O'Neill's horse was killed."
O'Neil later served with Teddy Roosevelt and the Rough Riders and was killed in action.
"Teddy Roosevelt wrote about the death of O'Neill: "The most serious loss that I and the regiment could have suffered befell just before we charged. Bucky O'Neill was strolling up and down in front of his men, smoking his cigarette, for he was inveterately addicted to the habit. He had a theory that an officer ought never to take cover - a theory which was, of course, wrong, though in a volunteer organization the officers should certainly expose themselves very fully, simply for the effect on the men; our regimental toast on the transport running, " The officers; may the war last until each is killed, wounded, or promoted." As O'Neill moved to and fro, his men begged him to lie down, and one of the sergeants said, " Captain, a bullet is sure to hit you." O'Neill took his cigarette out of his mouth, and blowing out a cloud of smoke laughed and said, " Sergeant, the Spanish bullet isn't made that will kill me." A little later he discussed for a moment with one of the regular officers the direction from which the Spanish fire was coming. As he turned on his heel a bullet struck him in the mouth and came out at the back of his head; so that even before he fell his wild and gallant soul had gone out into the darkness."
Route 66Two Guns Arizona