Conversation so far:
What did Wally Schirra do in the Apollo program?
Wally Schirra was assigned to command a three-man Apollo crew
What did the three-man Apollo crew assigned to Wally Schirra do?
to make the second crewed flight test of the Apollo Command/Service Module, with a mission profile identical to Apollo 1

Question: How did Schirra get involved with the Apollo program?
Self-contained rewrite: How did wally Schirra get involved with the Apollo program he was assigned to?