In watching this series, I learned about Mabel Walker Willebrandt, the Assistant Attorney General from 1921 to 1929 and was known as "the First Lady of the Law." The PBS documentary describes her as "an incredibly serious, determined, totally honest person who was told she had to enforce the law. So she was going to enforce the law." In her role, Willebrandt took on cases related to taxes and prisons, but most famously, she was a strong enforcer of the Volstead Act, more commonly known as the Prohibition Act.
At age 32, she was appointed Assistant Attorney General by President Warren G. Harding at the urging of California Republicans. It sounds like a very great honor, but it wasn't, really- the job had very few political advantages, so they thought they might as well give it to a woman.
Willebrandt had not been at all active in the Temperance movement. She even liked having drinks. But when she got the job, she became a teetotaler and went about her job with a great deal of effort because she believed herself to be "an instrument of God." And she had a lot of work to do. Willebrandt didn't think the Volstead Act was strong enough for her to take action against and bring lawbreakers to justice. She had no confidence in her boss, whom she considered to be supremely unqualified. She thought the Prohibition agents that worked for her were useless, as many of them were preachers and other men that had not been trained at all in how to be FBI agents. But she kept going, petitioning for a fleet of ships to patrol the waters against smugglers and worked with the Treasury Department to put the big-time bootleggers behind bars, most notably the Big Four of Savannah.
Willebrandt was also a strong supporter of prison reform and was successful in establishing a separate prison for women in West Virginia. She campaigned strongly for Herbert Hoover in the 1928 election year (earning the nickname "Prohibition Portia") but was disappointed when he thanked her for her efforts by booting her out of her job. She returned to private practice and worked to get commercial air travel approved in the US. She even met Amelia Earheart.
Willebrandt died in 1963, which is a shame as she missed much of the women's and civil rights movements. I think she would have been a strong and vocal supporter of both.