Conversation so far:
What were the USO tours?
The USO tours were tours to provide morale and recreation services to U.S. uniformed military personnel.
When did he start the USO tours?
Overseas shows began in November 1941 with a tour of the Caribbean.
Was Joe E. Brown a soldier in World War Two?
Aged 50 when the US entered World War II, Joe E. Brown himself was too old to enlist.
How would Joe E. Brown entertain troops?
Bob E. Brown gave shows in all weather conditions, many in hospitals, sometimes doing his entire show for a single dying soldier. He would sign autographs for everyone.

Question: What sort of work was he doing?
Self-contained rewrite: What sort of work was Joe E. Brown doing?