Prior to an NFL team moving to Baltimore, there had been several attempts at a professional football team prior to the 1950s.
Most were minor league or semi-professional teams.
The first major league to base a team in Baltimore was the All-America Football Conference (AAFC), which had a team named the Baltimore Colts.
The AAFC Colts played for three seasons in the AAFC (1947, 1948, and 1949), and when the AAFC folded following the 1949 season, moved to the NFL for a single year (1950) before going bankrupt.
Three years later, the NFL's Dallas Texans would itself fold, and its assets and player contracts purchased by an ownership team headed by Baltimore businessman Carroll Rosenbloom, who moved the team to Baltimore, establishing a new team also named the Baltimore Colts.
During the 1950s and 1960s, the Colts were one of the NFLs more successful franchises, led by Pro Football Hall of Fame quarterback Johnny Unitas who set a then-record of 47 consecutive games with a touchdown pass.
The Colts advanced to the NFL Championship twice (1958 & 1959) and Super Bowl twice (1969 & 1971), winning all except Super Bowl III in 1969.
After the 1983 season, the team left Baltimore for Indianapolis in 1984, where they became the Indianapolis Colts.

The NFL returned to Baltimore when the former Cleveland Browns moved to Baltimore to become the Baltimore Ravens in 1996.
Since then, the Ravens won a Super Bowl championship in 2000 and 2012, six AFC North division championships (2003, 2006, 2011, 2012, 2018, and 2019), and appeared in four AFC Championship Games (2000, 2008, 2011 and 2012).

Baltimore also hosted a Canadian Football League franchise, the Baltimore Stallions for the 1994 and 1995 seasons.
Following the 1995 season, and ultimate end to the Canadian Football League in the United States experiment, the team was sold and relocated to Montreal.
Prior to an NFL team moving to Baltimore, there had been several attempts at a professional football team prior to the 1950s. Most were minor league or semi-professional teams. The first major league to base a team in Baltimore was the All-America Football Conference (AAFC), which had a team named the Baltimore Colts. The AAFC Colts played for three seasons in the AAFC (1947, 1948, and 1949), and when the AAFC folded following the 1949 season, moved to the NFL for a single year (1950) before going bankrupt. Three years later, the NFL's Dallas Texans would itself fold, and its assets and player contracts purchased by an ownership team headed by Baltimore businessman Carroll Rosenbloom, who moved the team to Baltimore, establishing a new team also named the Baltimore Colts. During the 1950s and 1960s, the Colts were one of the NFLs more successful franchises, led by Pro Football Hall of Fame quarterback Johnny Unitas who set a then-record of 47 consecutive games with a touchdown pass. The Colts advanced to the NFL Championship twice (1958 & 1959) and Super Bowl twice (1969 & 1971), winning all except Super Bowl III in 1969. After the 1983 season, the team left Baltimore for Indianapolis in 1984, where they became the Indianapolis Colts.
The NFL returned to Baltimore when the former Cleveland Browns moved to Baltimore to become the Baltimore Ravens in 1996. Since then, the Ravens won a Super Bowl championship in 2000 and 2012, six AFC North division championships (2003, 2006, 2011, 2012, 2018, and 2019), and appeared in four AFC Championship Games (2000, 2008, 2011 and 2012).
Baltimore also hosted a Canadian Football League franchise, the Baltimore Stallions for the 1994 and 1995 seasons. Following the 1995 season, and ultimate end to the Canadian Football League in the United States experiment, the team was sold and relocated to Montreal.
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