Florence Ellinwood Allen
While not the first woman to wear a robe, on November 2, 1920, Florence Ellinwood Allen became the first woman elected to a judicial office in the United States when she won a judgeship on the Cuyahoga County Court of Common Pleas in Ohio.
At the time, material witnesses would be held in custody waiting for trial, while the defendants were free on bail. In the absence of a presiding judge, material witnesses could spend months in jail waiting for their case to be on the docket.
Allen worked to pass a law requiring a chief justice in any common-pleas courts with more than one judge. The move resulted in cases being adjudicated in a timelier manner, reducing the time the witnesses were held in custody.
Two years later, on November 7, 1922, Justice Allen again made history by becoming the first woman elected to the highest court in any state when she became a justice of the Supreme Court of Ohio.
At the bottom of the fourth page of the Friday, July 22, 1921 edition of the New York Times, stuck between the pronouncement of Chief Justice Taft’s new secretary and a notice about a garden party the previous afternoon, was a two-sentence piece announcing the nomination of Mary O’Toole to be a judge of the municipal court in the District of Columbia.
It was a rather humble introduction for the first woman to serve as a municipal court judge.
Just a few years later, E. E. Dudding, national president of the Prisoners’ Aid Society, urged the Department of Justice to appoint Judge O’Toole fill a vacancy on the D.C. Supreme Court:
There is no better lawyer in Washington or anywhere else…She knows the law. She is judicial. She would make one of the best judges to be found and would, I think, raise public opinion of Federal courts.
Hortense Sparks Ward (pictured left), Ruth Virginia Brazzil, and Hattie Lee Hennenberg
In 1925 the Texas State Supreme Court found itself in a conundrum. A dispute had arisen over whether the trustees of the Woodmen of the World were entitled to ownership of two tracts of land. The sticking point: The Woodmen of the World was a fraternal organization whose membership included all three justices of the Texas Supreme Court.
The three male justices recused themselves, and Governor Pat Neff appointed three women. Two of Governor Neff’s original appointments, Nellie Robertson and Edith Williams, withdrew, not having the statutorily required years of experience. Ruth Virginia Brazzil and Hattie Lee Hennenberg were then appointed to join Special Chief Justice Hortense Sparks Ward as the first all-female state supreme court.
Judge Bolin (pictured right) was just 31 when she became the first black female to serve as a judge in the United States. Judge Bolin sat on the bench for 40 years, spending 20 of those years as the only black female judge in the country.
An advocate for children’s rights, Judge Bolin worked to end segregation in child services and the use of ethnic background as a factor in probation officer assignment and funding for childcare agencies.
Julia Cooper Mack
Julia Cooper Mack became the first woman of color appointed to a court of last resort in the United States when she was appointed to the District of Columbia Court of Appeals in 1975.
Before taking the bench, Judge Mack was the Justice Department’s first female black attorney. Judge Mack’s accolades are not limited to her gender and achievement of breaking the racial ceiling. She is also credited with having authored “some of the best employment law decisions applying to [the Washington D.C.] civil rights act.” 
Judge Mack also helped shaped both the federal and state benches through the many young attorneys who would work for her. One such person is Judge Allyson Duncan. After clerking for Judge Mack, whom she called her hero, Judge Duncan went on to become “the first African-American woman and the first woman from North Carolina to sit on the influential U.S. Court of Appeals for the Fourth Circuit. She was the first African-American president of the N.C. Bar Association.”
 Andrea Simakis, “Before RBG, a Cleveland Judge Made History; It’s Time to Recognize Unstoppable Florence Allen,” Cleveland.com (July 1, 2019).
 “Appoints Woman as Judge; President Names Mary O’Toole to Washington Municipal Court,” New York Times, July 22, 1921; “Mary O’Toole, Municipal Judge,” Library of Congress.
 David A. Furlow, “All-Woman Court Ruled the State Bar Annual Meeting,” Journal of the Texas Supreme Court Historical Society 5, no. 4 (2016): 82-89.
 “Jane Bolin,” Wikiwand; “Jan Matilda Bolin: A Different Kind of First Lady,” blog, Ask Black Julia (April 20, 2018); “Mayor Administers Oath to Negro Woman as Justice of the Domestic Relations Court,” New York Times (July 23, 1939).
 Matt Schudel, “Julia Cooper Mack, D.C. Appellate Judge, Dies at 93,” Washington Post (January 30, 2014).