original_query: What is the color line in American baseball?
query: What is the color line in American baseball?
answer: The color line, also known as the color barrier, in American baseball excluded players of black African descent from Major League Baseball and its affiliated Minor Leagues until 1947.  This segregation was sometimes called a gentlemen's agreement, a tacit understanding without a written policy.  It began formally after the 1867 baseball season and was broken by Jackie Robinson's signing with the Brooklyn Dodgers in 1946.