In 1961, he and King moved to Atlanta since the city was becoming an important center for activism. When the Freedom Riders came to the city, Abernathy organized a rally at his church, West Hunter Street Baptist Church, to support the riders. They were attacked by an angry white crowd so Abernathy told them to go inside. There, he remained calm and resolute in the face of danger, a quality that did not go unnoticed by King and other movement leaders.
On April 12, 1963 (Good Friday), Abernathy, King and another activist, Fred Shuttlesworth, lead a protest in Birmingham and were arrested. This proved to be an important moment for the movement because King would write the seminal document of the Civil Rights Movement called Letters from a Birmingham Jail. This was his response to white clergymen who called for the movement to stop protesting and instead focus on advancing social justice issues through the electoral process. On August 28th, Abernathy, King and many other leaders of the movement led a large protest march on Washington D.C. calling for civil and economic rights. King gave his famous I Have a Dream speech on the steps of the Abraham Lincoln Memorial. Abernathy also participated in the Selma to Montgomery March in 1965, which paved the way for the Voting Rights Act.
Abernathy assumed the leadership of the Southern Christian Leadership Conference after King was killed, a position he would hold until 1977. He did not have the charisma that King had but continued to work for social justice and his ministry. He published a memoir titled And the Walls Came Tumbling Down in 1989 which is linked below along with other books and articles. Abernathy passed away in 1990.