1890: American Woman Suffrage Association and National Woman Suffrage Association merge into the National American Woman Suffrage Association. 

January 25, 1887: The United States Senate voted on woman suffrage for the first time -- and also for the last time in 25 years. 

1893 - Henrietta begins work at Harvard College Observatory 

1908 - Henrietta first published her data - noting a pattern in variable stars

May 4, 1912: Women marched up Fifth Avenue in New York City, demanding the vote. 

1912 - Henrietta publishes a full paper documenting her Period -Luminosity  relationship

1913 - Ejnar Hertzsprung uses Henriett'a finding to measure distance to cepheids within the Milky Way.

April 1917 - The United States government declares war against Germany - WW1 

June 1917: Arrests began of Suffrage pickets at the White House. 

January 10, 1918: House of Representatives passed the Anthony Amendment but the Senate failed to pass it.

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Nov 1918 - WW1 ends

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May 21, 1919: United States House of Representatives passed the Anthony Amendment again.

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June 4, 1919: United States Senate approved the Anthony Amendment. 

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1920 - Henrietta made head of Stella Photometry

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August 26, 1920 -  United States Secretary of State signed the Anthony (19th) Amendment into law.

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Dec 12th, 1921 - Henrietta dies of ovarian cancer

1923-24 - Edwin Hubble measures Cepheids in Andromeda Galaxy proving that the universe is far bigg than the Milky Way

1926 - Unaware of her death four years prior, the Swedish mathematician Gösta Mittag-Leffler considered nominating her for the 1926 Nobel prize in physics.