International Women's Day (IWD), originally called International Working Women's Day, is celebrated on March 8 every year.It commemorates the movement for women's rights.
The earliest Women's Day observance was held on February 28, 1909, in New York and organized by the Socialist Party of America,On March 8, 1917, in the capital of the Russian Empire, Petrograd, a demonstration of women textile workers began, covering the whole city. This was the beginning of the Russian Revolution. Seven days later, the Emperor of Russia Nicholas II abdicated and the provisional Government granted women the right to vote. March 8 was declared a national holiday in Soviet Russia in 1917. The day was predominantly celebrated by the socialist movement and communist countries until it was adopted in 1975 by the United Nations.
Original Content source - https://en.wikipedia.org/wiki/International_Women's_Day