Dave Rudabaugh asks Sam Bass, "What kind of cards are you going to deal Carver?" Bass answers, "Aces and eights; Dead Man's Hand!"
This is a reference to the hand that was held by Wild Bill Hickok when he was shot to death in a saloon. This movie is set in 1874; Hickok was not killed until two years later, in 1876.
Ranger Johnny Carver offers the little boy (Jimmy) a "Cartwheel" to take his horse down the street. "Cartwheel" is a nickname for the Morgan Silver Dollar. This story is set in the year 1874, but the Morgan Silver Dollar was not minted until four years later, in 1878.
Toward the end of movie the sign of elevation of Little River,Texas shows to be 1681'.
Towards the end of the movie the elevation sign of Round Rock, Texas, is shown to be 1861'.