"The 19th Amendment gave women the right to vote nationally on August 18, 1920, so why is Women’s Equality Day on August 26th each year?
The simple answer is that even when a constitutional amendment has been ratified it’s not official until it has been certified by the correct government official. In 1920, that official was U.S. Secretary of State Bainbridge Colby. On August 26, 1920, Colby signed a proclamation behind closed doors at 8 a.m. at his own house in Washington, D.C, ending a struggle for the vote that started a century earlier." -- Constitution Center
The first executive secretary of the League of Women Voters, Minnie Fisher Cunningham, was a Texan who, among many other notable achievements, worked for the passage of the 19th Amendment in Texas and nationally.
-- Alice Paul Org: https://www.alicepaul.org/2020-exhibition/
-- Constitution Center: https://constitutioncenter.org/blog/why-august-26-is-known-as-womans-equality-day
-- LOC: https://www.loc.gov/collections/women-of-protest/articles-and-essays/tactics-and-techniques-of-the-national-womans-party-suffrage-campaign/
-- NCSL: https://www.ncsl.org/research/about-state-legislatures/amending-the-u-s-constitution.aspx