Deciding to follow her father into the legal profession, she enrolled at the Baltimore Law School, and became its first female graduate in 1901.  Ms. Maddox then submitted her application to the Maryland Court of Appeals for permission to take the bar exam.  The court refused on the basis that Maryland law restricted the practice of law to "any male citizen of Maryland."

Ms. Maddox took her case to the Maryland legislature, requesting that a bill be introduced that would make it legal to admit women to the Maryland bar.  She appeared before the Judiciary Committee, along with several other female lawyers from across the United States, in support of the pending legislation.  The legislature bill was passed, and became law in 1902.  That summer, she passed the bar exam with distinction, and on September 11, 1902, was sworn in as a member of the bar, thus becoming the first licensed woman lawyer in the state of Maryland.

Ms. Maddox practiced law for a number of years and, along with her sister Emma Funck, became involved in the women's suffrage movement.  As a founder of the Maryland Suffrage Association, organized in 1894, she authored Maryland's first suffrage bill, which was introduced during the 1910 session of the General Assembly.  Ms. Maddox, along with over 400 suffragists from across the country attended a hearing in the House of Delegates to support the bill.  The bill was tabled, and Maryland rejected women's right to vote until the United States Constitution was amended, in 1920.

After 1920, the Maryland Suffrage Association became the Women's Democratic Club of Baltimore, and its members continued to press for social changes.  These included the use of public schools for social centers, equal pay for equal service, the appointment of women to boards of education and other public institutions, coeducation, and the abolition of capital punishment and child labor. 

Ms. Maddox spent her entire adult life fighting for women's rights.  Her courage, enthusiasm and desire to fight for what she believed was rightly hers remain inspiring today.  Upon being named one of Maryland's Top 100 Women in 2001 by The Daily Record, the Honorable Judge Ellen Moses Heller recognized Etta Maddox for paving the way for women in the law by saying, "I admire her determination, tenacity and individuality in pursuing a profession that had traditionally been closed to women."  Ms. Maddox's revolutionary accomplishments allowed women's voices to be heard.  Her endeavors laid a solid foundation for future activists to build upon.