It was just five months after the U.S. Supreme Court outlawed racial segregation in restaurants and waiting rooms of terminals serving buses and trains that crossed state lines. On May 4, 1961, 13 young activists set out on a bus tour of the Deep South to dramatize the fact that the law of the land went unenforced.

See also: 50 years later, students retrace a historic Freedom Ride.

By the end of the year, hundreds of other Freedom Riders — black and white — had joined efforts sponsored by the Congress of Racial Equality (CORE) and the Student Nonviolent Coordinating Committee (SNCC) and headed for Mississippi, Alabama, Louisiana, South Carolina, North Carolina, Georgia, Florida and Arkansas. They willingly exposed themselves to firebombing and other forms of mob violence, some of it instigated by the Ku Klux Klan. Most of the Freedom Riders were arrested and jailed.

"These courageous freedom riders have faced ugly and howling mobs in order to arouse the dozing conscience of the nation," Martin Luther King Jr. said at the time. "Some of them are now hospitalized as a result of physical injury. They have accepted blows without retaliation. One day all of America will be proud of their achievements."

This year marks the 50th anniversary of the 1961 Freedom Rides, a defining — and perhaps transforming — moment in the civil rights movement. (It's also the year the Martin Luther King Jr. memorial will open in the nation's capital.)

A few years ago, after discovering the mug shots of 328 Freedom Riders who had been arrested and jailed in Mississippi in 1961, journalist Eric Etheridge decided to locate, interview and photograph as many of them as he could find. The following portraits and profiles are adapted from his 2008 book, Breach of Peace.

First profile: The preacher >>