WASHINGTON (AP) — This week marks the start of the 50th anniversary of the civil rights Freedom Riders, who traveled by bus to confront segregation in the South.

Two buses carrying 13 Freedom Riders embarked from Washington 50 years ago Wednesday in 1961. They traveled south through Richmond, Va., Greensboro, N.C., and eventually to Rock Hill, S.C., where they met strong resistance.

Georgia Rep. John Lewis was among the Freedom Riders attacked at Rock Hill for attempting to enter a whites-only waiting room at the bus terminal.

The riders continued through Georgia and Alabama, facing firebombs and the Ku Klux Klan. They completed their journey to New Orleans by plane before returning to Mississippi.

This month, students will retrace the Freedom Rides. Also, PBS will premiere a new documentary on the subject.

Copyright 2011 The Associated Press.