Conversation so far:
What was Pershings first job?
Troop L of the 6th U.S.
Cavalry stationed at Fort Bayard, in the New Mexico Territory.
How did he get into this job?
also became an expert marksman and, in 1891, was rated second in pistol and fifth in rifle out of all soldiers in the U.S.
Army.

Question: How long was he with the U.S Cavalry?
Self-contained rewrite: How long was John J. Pershing with the U.S Cavalry?