On this date in 1881, the feud that had been brewing between the Earps and the Cowboys came to a head in Tombstone, AZ. Wyatt, Virgil, and Morgan Earp, along with their friend Doc Holliday, confronted Ike and Billy Clanton, Tom and Frank McClaury, and Billy Claiborne in a lot next to the OK Corral. Ike Clanton (who was unarmed) and Billy Claiborne fled the scene unscathed. Billy Clanton and the McClaury brothers stayed and shot it out with Holliday and the Earps. The gunfight lasted maybe 30 seconds, and when it was over, two of the Earps (Morgan and Virgil) and Doc Holliday were wounded, and Billy Clanton and the McClaury brothers were dead.
My 2007 blog post on the gunfight (with pictures from my trips to Tombstone)
Wikipedia: Gunfight at the O.K. Corral