Was there a team in Baltimore before the Colts?

Answer 1

Baltimore has had 2 professional football clubs before the Ravens:

NFL - Baltimore Colts

CFL - Baltimore Stallions

NFL - Baltimore Ravens

All 3 teams won championships in their respective leagues.

Answer 2

There was an All American Football Conference team, also called the Baltimore Colts, that joined the NFL (along with the Cleveland Browns and San Francisco 49ers) in 1950 when the AAFC folded. That team went 1-11 in 1950 and folded following the season when the owner, Abe Watner, sold the team back to the NFL for $50,000.

Hall of Famers George Blanda, Y.A. Tittle, and Art Donovan played for the 1950 Baltimore Colts.