“We the People of the United States,” she said, “in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defense, promote the general Welfare and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America.”

“Well, little lady,” one of the men conceded. “You did it.”

She registered and cast her ballot that year, 1942, becoming one of the state’s first black voters since Reconstruction. She voted in nearly every election thereafter. For more than 40 years, she was a county poll worker on election days, and a special registrar commissioner, helping some 4,000 people to register to vote.

In 1950, she joined the National Association for the Advancement of Colored People, and for more than 60 years participated in protests against racial discrimination, including the 1963 March on Washington for Jobs and Freedom.

During the civil rights turmoil of the 1960s, she and her family were threatened repeatedly by night riders, according to federal court papers. She awoke several times to the crackle of burning crosses outside her home. Farm equipment was damaged one night, and bullets were fired into a shed and into the farmhouse. One struck just below her bedroom window.

North Carolina’s effort, a half-century later, to impose restrictive changes on voting laws prompted Ms. Eaton to join a peaceful protest outside the Legislature in Raleigh in 2013. As she moved slowly with a walker, her friend, the Rev. Dr. William J. Barber II, then president of the North Carolina N.A.A.C.P., told her: “Rosanell, you don’t have to do this.”

“I know what I have to do,” she said.

The Rev. Dr. T. Anthony Spearman, who succeeded Dr. Barber last year as president of the North Carolina N.A.A.C.P., said on Sunday that Ms. Eaton had been an inspiration to generations of African-Americans in North Carolina.

“Mother Rosanell Eaton was a warrior for justice who gave the most for her people in an utterly selfless way,” Dr. Spearman told The Times. “She was wise to a fault, and extremely sensitive to the vitriolic climate of our times. She rose up to champion voting rights and her people.”