Actually, any and every month is a good time to celebrate women's history, but in 1987, Congress designated March as Women's History Month. The celebration originally began as a day, March 19, in 1911 and was expanded to a week in 1981. The choice of March as the month commemorates a women's garment workers protest in March 1857.
Consult our Women, Gender, and Sexuality resource list as well as our History list for relevant resources. One of my favorites is Women and Social Movements in the United States, 1600-2000. A search for Victoria Woodhull yields fascinating primary and secondary material on the first woman candidate for president. Looking for more primary sources including collections that are only on microfilm? Check out our Women, Gender, and Sexuality subject guide.