Earp moved constantly throughout his life from one boomtown to another. He left Dodge City in 1879 and moved with brothers James and Virgil to Tombstone, where a silver boom was underway. The Earps clashed with an informal group of outlaws known as the "Cowboys". Wyatt, Virgil, and younger brother Morgan held various law-enforcement positions which put them in conflict with Tom McLaury, Frank McLaury, Ike Clanton, and Billy Clanton who threatened to kill the Earps on several occasions. The conflict escalated over the next year, culminating in the shootout at the O.K. Corral on October 26, 1881, where the Earps and Doc Holliday killed three Cowboys. During the next five months, Virgil was ambushed and maimed, and Morgan was assassinated. Wyatt, Warren Earp, Doc Holliday, and others formed a federal posse which killed three more Cowboys whom they thought responsible. Wyatt was never wounded in any of the gunfights, unlike his brothers Virgil and Morgan or his friend Doc Holliday, which only added to his mystique after his death.