Unlike the American Bar Association at the time, the NLG was racially integrated. In 1937, Hart became a founding member and the first national secretary of the National Lawyers Guild (NLG), a progressive organization founded to advance civil liberties and the rights of trade unions and immigrants. Just two years later she gained admission to the bar and became the first woman to serve as public defender in the Morals Court, which handled cases of adultery, prostitution, and child abuse (and eventually became the Women’s Court).
Hart’s career began in 1912 when, at the age of twenty-two, she began taking evening classes at John Marshall Law School, where she would later teach.
