Conversation so far:
What was Walter Cronkite's earliest job?
He entered broadcasting as a radio announcer for WKY in Oklahoma City, Oklahoma.
How long did Walter Cronkite stay with WKY?
He left WKY radio within a year.
What did Walter Cronkite do after leaving WKY?
Walter Cronkite was a sports announcer at KCMO in 1936 with the on air name of Walter Wilcox.
What did Walter Cronkite do for United Press International?
He became one of the top American reporters in World War II, covering battles in North Africa and Europe.

Question: When did he leave the United Press?
Self-contained rewrite: When did Walter Cronkite leave United Press International?