Conversation so far:
when did the philadelphia eagles start playing football
The Eagles have been a Philadelphia institution since their beginning in 1933.
why are the philadelphia eagles called the eagles
Bert Bell and Lud Wray named the team the Eagles in honor of the symbol of the National Recovery Act, which was part of President Franklin D. Roosevelt’s New Deal.

Question: what was the symbol
Self-contained rewrite: what was the symbol of the national recovery act