Spider Martin makes a photograph of Brown Chapel A.M.E. Church in the reflection of a Birmingham News reporter’s sunglasses. His caption written in 1965, describes his time on the March.

Andrew Young leads a prayer with Amelia Boynton, Hosea Williams, John Lewis and Bob Mants before the first march to Montgomery, March 7, 1965.

Arms linked, Bob Mants, John Lewis, Hosea Williams and Andrew Young sing freedom songs with marchers outside Brown Chapel AME Church before beginning the first march to Montgomery, March 7, 1965.

John Lewis, Hosea Williams, Albert Turner, Bob Mants and Charles Mauldin lead the first march to Montgomery across the Edmund Pettus Bridge on March 7, 1965.

Alabama state troopers in tear-gas masks await the marchers at the foot of the Edmund Pettus Bridge.

The Rev. Hosea Williams, John Lewis, Albert Turner, Bob Mants, Charles Mauldin and other participants in the March for Voting Rights from Selma to Montgomery, Alabama were confronted by Alabama state troopers just after crossing the Edmund Pettus Bridge outside Selma on Bloody Sunday, March 7, 1965. March participants were ordered to disperse, then were almost immediately attacked by state troopers and horsemen armed with clubs and tear-gas, assaulting the protestors who fled back to Selma. Spider Martin’s most iconic image is known as “Two Minute Warning.”

Troopers overwhelm demonstrators in a full-on brutal assault on Bloody Sunday.

A close-up detail of John Lewis as he’s attacked by a trooper with a billy club resulting in a concussion.

After being beating unconscious by a trooper, 54 year old Amelia Boynton lies on the ground.

Marchers flee across the bridge as an unidentified woman assists a still-unconscious Amelia Boynton.

Marchers lift Amelia Boynton as the troopers force the protest back over the bridge.

A Dallas County sheriff’s deputy wields a tear-gas launcher during the Bloody Sunday confrontation.

Troopers continue their assault on retreating marchers with tear-gas and billy clubs.

Tear-gas overwhelms the scene as marchers continue to flee or fall to the blows of troopers.

State troopers and Sheriff Jim Clark’s posse pursue the marchers back over the bridge to Brown Chapel AME Church after the attacks on Bloody Sunday.

The patient log from Good Samaritan Hospital in Selma shows names of the marchers admitted on March 7, 1965 after the Bloody Sunday attacks including Amelia Boynton who was clubbed unconscious by a trooper and John Lewis who suffered a skull fracture.

Selma’s Director of Public Safety, Wilson Baker, receives a telegram from a resident of Framington, Massachusetts reacting to news of the Bloody Sunday violence.

Marchers hold signs protesting police brutality that ended the Bloody Sunday March.

Alabama state troopers form a roadblock on the far side of the Edmund Pettus Bridge.

Outside Brown Chapel AME Church, a young demonstrator keeps warm under a quilt while waiting for permission to march.

Students sing freedom songs in the rain and cold outside Brown Chapel Church while awaiting permission to march.

Students sing freedom songs in the rain and cold outside Brown Chapel Church while awaiting permission to march.

Dr. Martin Luther King Jr., Ralph Abernathy and Archbishop Iakovos attend a memorial service for James Reeb. Reeb, a white Unitarian minister from Massachusetts who had answered Dr. King’s call for religious leaders to join the protests, was brutally attacked as he left a local black-owned restaurant on March 9, he died two days later from his injuries.

Marchers lay a wreath on the steps of the Dallas County Courthouse after James Reeb’s memorial service.

With tensions high after Bloody Sunday and James Reeb’s death, Dr. King gives a press conference to talk about a planned voting rights march to the Montgomery County Courthouse while awaiting Federal Judge Frank M. Johnson’s ruling to permit the third march attempt from Selma to Montgomery.

Ralph Abernathy, James Forman, Dr. Martin Luther King Jr. and Rev. S.L. Douglas lead the voting rights march to the Montgomery County Courthouse, March 17, 1965.

Ralph Abernathy, James Forman, Dr. Martin Luther King Jr. and Rev. S.L. Douglas and John Lewis lead the voting rights march to the Montgomery County Courthouse, March 17, 1965.

Dr. King and demonstrators get caught in a sudden rain shower as they take the march past the Alabama State Capitol to the Montgomery County Courthouse.

A student voting rights march takes place at the Capitol during Dr. King’s press conference in conjunction with Dr. King’s march to the Montgomery County Courthouse.

After a day marching through Montgomery, James Bevel, Andrew Young and Dr. Martin Luther King Jr. are captured in a pensive moment at Montgomery’s Air National Guard Base, Dannelly Field before leaving Alabama.

News media, local police and members of the military swarm around Selma’s Brown Chapel AME Church as 3,200 voting rights demonstrators prepare to march to Montgomery, March 21, 1965.

Spider Martin photographed this scene from the roof of Brown Chapel AME Church of the 3,200 demonstrators preparing to march to Montgomery, March 21, 1965.

Rev. Ralph Abernathy and Dr. Martin Luther King Jr. captured in a pensive moment at the start of the first day’s march to Montgomery, March 21, 1965. Rev. Abernathy wears a lei, one of several airmailed to march leaders by a Hawaiian minister, Abraham Akaka.

As the third march makes its way through the site of the Bloody Sunday attack, Spider ran to climb a nearby billboard in order to get this wide shot and captured Dr. Martin Luther King Jr., Ralph Abernathy and John Lewis just before they marched out of frame.

At the foot of the Edmund Pettus Bridge, hecklers with a confederate flag offer a counter-protest.

Exuberant joyful marchers make their way with bags and suitcases in hand on the first day of the long 54 mile march to Montgomery.

The march makes it’s way through rural sharecropper communities on the arduous trek toward Montgomery.

A group of people, likely families living together in a sharecropper house, wave at marchers along the Highway 80 route to Montgomery.

The march makes it’s way through Lowndes County under the federalized Alabama National Guard and US Military police units.

A billboard in a field along the Selma to Montgomery March route shows Dr. Martin Luther King Jr. at a 1957 event at the Highlander Folk School, an attempt to discredit King by associating him with communism.

Jim Letherer, a settlement house worker from Michigan, completed the entire 54 mile march on crutches.

This marcher was nicknamed “Sunshine” for her beautiful smile and lively energy throughout the march.

Black and white young women marching in arms sing freedom songs along the Highway 80 route to Montgomery.

Black and white demonstrators march with the American flag held upside down as a signal of distress.

The march makes it’s way over Big Swamp Creek in Lowndes County under the federalized Alabama National Guard and US Military police units.

Spider Martin described this photo of John Lewis, Dr. Martin Luther King Jr., Rev. Ralph Abernathy and James Bevel singing freedom songs as they walked past an antebellum home as one of his favorites because of the poignant symbolism.

An unidentified minister, John Lewis, Rev. Ralph Abernathy, Dr. Martin Luther King Jr. and S.N.C.C (Student Nonviolent Coordinating Committee) workers take a rest from marching.

A voting rights marcher holds an American flag upside down as he joins thousands of other marchers in the final Selma to Montgomery March, March 21-25, 1965.

Spider Martin photographs the march to Montgomery from the vantage point of a tree over US 80 also know as the Jefferson Davis Highway.

An unidentified marcher wears a Levis jacket with artwork inspired by the soul singer Nina Simone’s song Mississippi Goddam. Her iconic protest song about violence against civil rights activist Medgar Evers, the Four Little Girls killed in the bombing at 16th Street Baptist Church in Birmingham, Alabama and the thousands of Freedom Fighters across the South.

A voting rights demonstrator rests on the highway asphalt after hours of marching to Montgomery.

Dr. King and Rev. Ralph Abernathy take a short break from marching to have coffee and a bite of food with one of the many women on the march.

An exhausted minister from Maine rests his head on his knees in the muddy field of one of the designated campsites along the march route to Montgomery.

A marcher’s blistered feet bear witness to the grueling nature of the 54- mile march to Montgomery.

Dr. Martin Luther King Jr. and Coretta Scott King arrive at Montgomery Air National Guard Base - Dannelly Field to meet with a coordinator for the Stars For Freedom Rally held hours later on the final night of the Selma to Montgomery March, March 24, 1965.

Dr. Martin Luther King Jr. and his wife Coretta Scott King, enjoy the “Stars for Freedom” rally.

As the third and final march nears it’s conclusion, Amelia Boynton, John Lewis, Rosa Parks, Rev. Ralph Abernathy, Jean Young, Ralph Bunche, Dr. Martin Luther King Jr., Coretta Scott King, Rev. Frederick D. Reese and Hosea Williams stop to prepare the line.

Rev. Ralph Abernathy, Juanita Abernathy, Ralph Bunche, Dr. Martin Luther King Jr., Coretta Scott King and Rev. Frederick D. Reese lead the march through downtown Montgomery to the Capitol, March 25, 1965.

Jubilant marchers arrive in Montgomery on March 25, 1965.

Counter-protestors awaiting voting rights marchers arrival into Montgomery demonstrate in front of the Capitol.

A pensive moment with a military police officer and a nun in front of the Capitol.

Counter-demonstrators raise confederate flags and signs with racist and offensive slurs to protest African American’s right to vote.

In the shadow of the state capitol, counter-demonstrators carry signs protesting the marchers and President Johnson’s support of the Civil Rights Movement.

The press and law enforcement surround counter-protestors as marchers arrive at the state capitol.

A counter-protester holds a sign depicting African Americans as savages at the closing rally of the Selma to Montgomery March, March 25, 1965.

A crowd of 25,000 converge in front of the Capitol to listen to speeches at the end of the 4 day Selma to Montgomery March on March 25, 1965.

Dr. Martin Luther King Jr. speaks to the crowd at the march’s end.

Dr. Martin Luther King Jr. delivers his famous “How Long, Not Long” speech near the Capitol steps.

Spider Martin takes his selfie with the Alabama State Capitol and 25,000 people in the background to document his 5 weeks and final day of his time on the March.

Viola Liuzzo, a Detroit housewife compelled to come to Selma to volunteer after witnessing on TV the violence of Bloody Sunday, was shot dead by three KKK members only hours after Dr. Martin Luther King delivered his “How Long, Not Long” speech at the Alabama State Capitol during the climax of the Selma to Montgomery March. Liuzzo was driving African American civil rights worker, Leroy Moton, back from shuttling activists between Selma and Montgomery. A state trooper photographs her car while authorities examine the crime scene.