Carter was born in Atlanta in 1899, the daughter of William Alphaeus Hunton, Sr. (founder of the black division of the Y.M.C.A.) and Addie Waites Hunton (a social worker); both were college educated.
Carter graduated from Smith College in Northampton, Massachusetts, where she received a Bachelor’s and a Master’s degree. After working briefly as a social worker, she decided to study law. She became the first black woman to receive a law degree from Fordham University in New York City. Carter passed the New York bar exam in 1933.
In 1935 Carter became the first black woman assistant district attorney in the state of New York. As an assistant DA, Carter put together a massive prostitution racketeering case that led eventually to Mafia boss Lucky Luciano. Carter convinced New York District Attorney Thomas Dewey to personally prosecute the case. Luciano was convicted and served ten years, and then was deported. Hunton married Lisle Carter, Sr., who was one of the first African-American dentists in New York.