In the summer of 1962, Hamer made a life-changing decision to attend a protest meeting. She met civil rights activists there who were there to encourage African Americans to register to vote. Hamer was one of a small group of African Americans in her area who decided to register themselves. On August 31, 1962, she traveled with 17 others to the county courthouse in Indianola to accomplish this goal. They encountered opposition from local and state law enforcement along the way.
Such bravery came at a high price for Hamer. She was fired from her job and driven from the plantation she had called home for nearly two decades—just for registering to vote. But these actions only solidified Hamer's resolve to help other African Americans get the right to vote. According to The New York Times, she said "They kicked me off the plantation, they set me free. It's the best thing that could happen. Now I can work for my people."
Hamer dedicated her life to the fight for civil rights, working for the Student Nonviolent Coordinating Committee. This organization was comprised mostly of African-American students who engaged in acts of civil disobedience to fight racial segregation and injustice in the South. These acts often were met with violent responses by angry whites. During the course of her activist career, Hamer was threatened, arrested, beaten, and shot at. She was severely injured in 1963 in a Winona, Mississippi jail. She and two other activists were taken in by police after attending a training workshop. Hamer was beaten so badly that she suffered permanent kidney damage.