During the Civil Rights Movement, Dahmer served two terms as president of the Forrest County Chapter of the National Association for the Advancement of Colored People (NAACP) and led voter registration drives in the 1960s. His wife Ellie said "He was a good progressive Christian man. He wasn't a mean, bitter Civil Rights worker, because he saw good in white as well as he did in black." As president of the Forrest County Chapter of the NAACP, he had personally asked the Student Nonviolent Coordinating Committee (SNCC) to send workers to help aid the voter registrations efforts being made by African Americans in Hattiesburg, Mississippi. SNCC had sent two workers, Curtis Hayes and Hollis Watkins, to Hattiesburg. The act of calling SNCC to help aid the efforts made by the NAACP would eventually cost him his NAACP presidency.