Women in Chess - First women-only event. What was the first women-only event held in Chess history?
The First International Ladies' Chess Congress in London, 1897. Games commenced on June 23 and the tournament was finished on July 3. It was organized by the Ladies' Chess Club of London and the Women's Chess Club of New York. The time control was 20 moves per hour, from 1 to 5 pm and 7 to 11 pm. Two games were played per day.

Results (after 19 rounds):


Mary Rudge 18.5
Louisa Matilda Fagan 15.5
Eliza Mary Thorold 14
Harriet J. Worrall 13
Marie Bonnefin 12.5
F. Sterling Barry, Edith Margaret Thomas 11.5
Gertrude Field 11
G. Watson, A. M. Gooding 10.5
E. H. Sidney, Alice E. Hooke 10
Rita Fox 9
Anna Hertzsch 8.5
Eschwege 6
Müller-Härtung 5.5
De la Vigne, Forbes-Sharpe 4
Finn 3.5
Stevenson 1


Referee: Harry Nelson Pillsbury

My sources are


Batgirl: Women Can Play Chess!, 2013, chess.com
Joost van Winsen: The Ladies Made an International Move, 2016, chess archaeology (with many pictures!)