I've probably watched Tombstone 20 times now, and could watch it twenty more.
When the Earp's first enters Tombstone, a grave marker can be seen in the cemetery that reads "Here lies Lester Moore, Four slugs from a .44, No Les No more." There is an actual tombstone in Tombstone, Arizona that has that epitaph.
Also, Stephen Lang (played Ike Clanton) was legitimately tequila-drunk during all of his scenes. Takes some balls to be able to do that in fully woolen costumes during 110-degree weather, props to him.