International Women's Day is a celebration honoring women's accomplishments that have broken the glass ceiling. The first women's day was observed on Feb. 28, 1908, when 15,000 women marched through NYC demanding equal pay and the right to vote. The tradition continued from there on the last the Sunday in February until the year 1913. It wasn't until 1913 that a consensus was reached to celebrate women in March. The chosen date commemorates the women's march in Petrograd, Russia, which sparked the Russian Revolution in 1917.