This is what I discovered (Because I knew nothing when I bought it).
Prior to the Fair, there were some prominent early feminists (in Missouri) that were working tirelessly for Women's right to vote - and for Women's rights overall.
Though women's rights were beginning to get attention during the 1904 World's Fair, they still did not have the right to vote in Missouri. The "Show Me State" had to wait for the US Congress to pass the 19th Amendment to the Constitution which finally granted women the right to vote. On August 31, 1920, Marie Ruoff Byrum of Hannibal became the first woman voter in the state of Missouri.
Aware of the emerging feminist ideas of the time, the Fair's officials established a Board of Lady Managers. Composed of 23 women that represented every geographic of the country, the women helped set guidelines and decency codes (especially for the racy Pike attractions), at the 1904 Exposition. Mrs. James L. Blair was the first President of the Board, which was situated in the Physics Building at Washington University. The organizers also decided to not include a women's building at the Fair, as it would suggest an apartness rather than an integration of equality. There were many women exhibits at the State buildings and palaces, including prominent displays at the Palaces of Manufactures and Varied Industries. Mrs. Daniel Manning, who was once married to the US Secretary of the Treasury, used her influence and contacts to gain 4.5 million dollars for the Louisiana Purchase Exposition Company.
Now in terms of the postmark - I have to assume that because these Lady Managers were from all over, this particular Post Card went from Indiana to NY (from one Lady manager to another)confirming the receipt of a report from the fair -honestly that part I am not 100% sure on. :). Anyhow - If I hadn't picked up this card I would never have known a Board of Lady managers existed. Nora.