Frederick was one of the founding members of the Blue Ridge League, which existed from 1915 to 1930. The team, which went by the names of Hustlers, Champs and Warriors, won league championships in 1915 and 1921. Games were played at the Frederick Fairgrounds until 1924 when McCurdy Field was built. With the collapse of the Blue Ridge League in 1931, it would be several decades before professional baseball returned to Frederick. Frederick players from this era who were major leaguers:
Clyde Barnhart: 1915, 1916, 1917
Tom Connolly: 1915
Bill Lamar: 1915
Leo Meyer: 1916
Tom Crooke: 1917
Clarence Blethen: 1920, 1921, 1922, 1923
Ray Gardner: 1920, 1922, 1923, 1925
Ray Hartranft: 1920
Duke Sedgwick: 1922
Jim Keesey: 1923
Norm McNeil: 1923
Bobby Schang: 1923
Chick Fullis: 1924, 1925, 1926
Karl Kolseth: 1924
Bill Hohman: 1924
Rollie Hemsley: 1925, 1926, 1927
Larry Boerner:1926
Jimmie DeShong:1928
Joe Vosmik: 1929
Milt Galatzer: 1930
Bill Perrin: 1930
Debut
The team was founded in 1989 when the Baltimore Orioles decided to move their Class A affiliate from Hagerstown, Maryland. The city of Frederick convinced the owners of the then-Hagerstown Suns to move the team to Frederick and promised a 4,000-seat stadium to be built for the 1990 season. For the 1989 season, the Keys played at McCurdy Field, a Babe Ruth League stadium, while waiting for the construction of the new stadium to be completed. The Keys opened by losing both ends of a doubleheader against the Durham Bulls. Their first win came on April 11, 1989, with a 3–1 victory over the Kinston Indians in the Keys' first-ever home game. Only two players in Keys history have been transferred directly from Frederick to the Baltimore Orioles. On September 3, 1996, Eugene Kingsale's contract was purchased by the Orioles. On June 11, 2005, Jeff Fiorentino's contract was purchased by the Orioles in order to replace the injured Luis Matos. The Keys have played in the Carolina League Championship Series, the Mills Cup Series, five times. Four series were against the Kinston Indians, while the series in 2007 was against the Salem Avalanche. They won their first series in 1990, defeating the Indians three games to two. They won their second cup in the 2005 season, defeating Kinston three games to two at historic Grainger Stadium in the best of five series. They were swept by the Indians in 2006, 3 games to 0. They won the 2007 series against the Salem Avalanche three games to one. They defeated Kinston in the 2011 series three games to one.
2011: Defeated Potomac 3-2 in semifinals; defeated Kinston 3-1 to win championship.
2017: Lost to Lynchburg 2-1 in semifinals.
Notable former Keys
Several Keys alumni have gone on to play in the major leagues. In their inaugural season, the opening day roster featured several future major leaguers: David Segui, Francisco de la Rosa, Luis Mercedes, Jack Voigt, and Pete Rose, Jr. Other Keys alumni include: