Suffragist Mabel Vernon was born in Wilmington, Delaware in 1893, the daughter of George Washington Vernon, publisher of the newspaper the Republican, which later consolidated with the Evening Journal. She graduated from Wilmington Friends' School and received a B.A. from Swarthmore before joining the Congressional Committee of the National American Woman Suffrage Association. Soon after, she was asked to return to her home State to advocate for the cause

Delaware had the opportunity to become the state to make the decisive vote to ratify the Nineteenth Amendment. Vernon, along with local leaders Florence Bayard Hilles and Jean DuPont, traveled by convertible and used the car as her platform during her "street-corner campaign." In the Spring of 1920, the amendment came to a vote in Dover, where both sides picketed in what was called the "war of the roses," for the yellow roses worn by suffragists and the red ones worn by anti-suffragists. Despite the efforts of Vernon and other supporters, most of the Republicans in the Delaware legislature and Republicans from Wilmington opposed ratification and it was defeated. In 1923, the Amendment was symbolically ratified, three years after it became part of the Constitution.