Conversation so far:
When did Mickey Thompason start racing cars?
In his early 20s, Mickey Thompson became involved in the new sport of drag racing. Tireless and innovative, he found success as a championship driver and instinctive automotive technician.
Did Mickey Thompson ever race internationally?
No
What was the first race Mickey Thompson competed in?
Did Mickey Thompson ever crash any of his racing cars?
No

Question: How long did he race for?
Self-contained rewrite: How long did Mickey Thompson race for?