Conversation so far:
How did Calamity Jane get her nickname?
Jane was involved in several campaigns in the long-running military conflicts with Native Americans. Her claim was that: It was during this campaign that I was christened Calamity Jane.
What campaign did Calamity Jane gain the name from?
Calamity Jane gained her nickname in the 1872–73 campaign
Why was Calamity Jane given this nickname?
Capt. Egan, on recovering, laughingly said: I name you Calamity Jane, the heroine of the plains. I have borne that name up to the present time.

Question: Who gave her the nickname?
Self-contained rewrite: Who gave Calamity Jane the nickname?