Four girls received in death one of America's highest civilian awards Friday as the nation's first black president honored some of the youngest victims in the historic fight for equal rights.

In the Oval Office, President Barack Obama signed a bill designating the Congressional Gold Medal to the four girls killed on Sept. 15, 1963, when the 16th Street Baptist Church in Birmingham, Alabama, was bombed by a group of Ku Klux Klan members.

The girls' names were Addie Mae Collins, 14; Denise McNair, 11; Carole Robertson, 14; and Cynthia Wesley, 14. They died inside their Sunday school classrooms when dynamite, with a time-delay device attached, exploded and blew up the church. The attack, which killed the girls and injured 22 other churchgoers, marked a turning point in America's struggle for civil rights. Propelled in part by public outrage over the bombing, Congress passed the Civil Rights Act the next year.