In baseball—as in America—freedom is an ongoing quest. The game has mirrored American intolerance and efforts to end it. It has greeted immigrants welcomingly and warily, spawning bittersweet scenes such as wartime Japanese-American internees defying prejudice with bat and glove.

The history of American freedom is complex. That complexity is starkly visible when America is viewed through the prism of baseball.

Baseball has spanned a century and a half of profound social change. Its record of race relations parallels America's evolving attitudes.

After the Civil War, Reconstruction brought cautious change. Some professional teams allowed black players in the 1880s. They quickly stopped doing so, however, as new "Jim Crow" laws codified segregation in the South and the Supreme Court's 1896 Plessy v. Ferguson decision established "separate but equal" as national policy.

Barred from the white leagues, African-American and some Latino players responded by creating new teams, forerunners of the 1920s Eastern Colored League and Negro National League. Though color barriers began eroding in the 1940s, major league integration progressed slowly.

Immigrants and others facing discrimination or exclusion have often seen baseball as a doorway to American culture. But doors can swing open and shut, welcoming outsiders...or keeping outsiders out.

Photo: Denis Finnin, AMNH

For most of baseball's history, white teams barred African Americans and many Latinos because of their skin color. Irish, Poles, Jews, Italians, Asians, and others who have been victims of prejudice in America often faced slurs in the dugout or stands.

Baseball mirrors our complex, changing attitudes towards people of different backgrounds. The characters on "Brother Noah Gave Out Checks for Rain," a 1906 song sheet, reveal callous stereotypes of African Americans. Yet, more recently, Spanish accent marks on player jerseys illustrate increasing sensitivity to diversity.