Conversation so far:
who played wyatt earp's wife in the movie tombstone
Dana Delany plays Wyatt earp's wife Josephine Marcus
Who played Wyatt earp in the movie Tombstone
Kurt Russell played Wyatt Earp in the movie Tombstone
When was the movie Tombstone released
Tombstone was released December 25, 1993

Question: what is the movie based on
Self-contained rewrite: What is the movie Tombstone based on