Dan McClellan was an African American

African American

African Americans are citizens or residents of the United States who have at least partial ancestry from any of the native populations of Sub-Saharan Africa and are the direct descendants of enslaved Africans within the boundaries of the present United States...

 baseball

Baseball

Baseball is a bat-and-ball sport played between two teams of nine players each. The aim is to score runs by hitting a thrown ball with a bat and touching a series of four bases arranged at the corners of a ninety-foot diamond...

 pitcher

Pitcher

In baseball, the pitcher is the player who throwsthe baseball from the pitcher's mound toward the catcher to begin each play, with the goal of retiring a batter, who attempts to either make contact with the pitched ball or draw a walk. In the numbering system used to record defensive plays, the...

 in the Negro Leagues. He played regularly for major teams for at least a decade beginning 1903 and continued as a playing manager and organizer of lesser teams.

With the Cuban X-Giants

Cuban X-Giants

The Cuban X-Giants were an African-American professional baseball team for about ten seasons around 1900. Originally most of the players were former Cuban Giants, or ex-Giants....

 in 1903 he pitched the earliest known perfect game in black baseball. That team and the Philadelphia Giants

Philadelphia Giants

The Philadelphia Giants were a Negro league baseball team that played from 1902 to 1916. From 1904 to 1909 they were one of the strongest teams in black baseball, winning five eastern championships in six years. The team was organized by Sol White, H. Walter Schlichter, and Harry Smith.- Founding...

 of 1904 to 1906 were four consecutive recognized championship teams with Rube Foster and McClellan as regular pitchers. McClellan was a "smart pitcher ... to offset his lack of a substantial fastball".(Riley)

Named as "Dream Team" coach in the 1952 Pittsburgh Courier poll of outstanding black baseball players.