Born Essie Mae Moody on September 15, 1940, near Centreville, Mississippi, Moody was the daughter of poor African-American sharecroppers. She was the oldest of nine children.

She won a basketball scholarship to Natchez Junior College and was in attendance from 1959 through 1961. She then won an academic scholarship to Tugaloo College in Jackson, Mississippi, and received a bachelor of science degree in 1964.

While at Tugaloo, Moody became an activist in the civil rights movement, maintaining involvement with the Congress of Racial Equality (CORE), the Student Nonviolent Coordinating Committee (SNCC), and the National Association for the Advancement of Colored People (NAACP). In 1963, she was one of three young people who staged a sit-in at a segregated Woolworth's lunch counter in Jackson. She also took part in the 1963 march on Washington, D.C.

Moody worked in Canton, Mississippi, for more than a year with CORE to register African-American voters. She faced threats of violence and also was put on the Ku Klux Klan's blacklist during this period. From 1964 through 1965, Moody served as the civil rights and project coordinator at Cornell University.

Becoming disenchanted with certain aspects of the civil rights movement, Moody moved to New York City, where she began to write her autobiography, Coming of Age in Mississippi, which was published in 1968. The book has received several national awards.

Aside from her autobiography, Moody published Mr. Death: Four Stories (1975). Moody also worked as a counselor for the New York City Poverty Program.