From the League of Women Voters of Martha's Vineyard:

On August 26, 1920,  the 19th Constitutional Amendment, having been ratified by the state of Tennessee on August 18, 1920, was certified into law—enfranchising women with the power of the vote.    

In 1973, the U.S. Congress designated August 26 as Women's Equality Day.

To commemorate this historical milestone in women voter rights and to celebrate equality for all women, the Martha’s Vineyard Museum will be lighting the building Wednesday from 7 p.m. until midnight in the colors of the suffrage movement: purple, white and (sunflower) gold.