Conversation so far:
When did Walter Cronkite start his career?
In 1936.
what was walter cronkite's job?
Walter Cronkite entered broadcasting as a radio announcer.
what newspaper did Walter Cronkite write for?
In 1939 Walter Cronkite became a news editor for United Press.
when was walter cronkite first on air?
In 1936, Walter Cronkite worked as the sports announcer for KCMO (AM).

Question: What was his first big story?
Self-contained rewrite: What was Walter Cronkite's first big story? working for CBS?