Worlds of Women is an exploration of the "first wave" of the international women's movement, from its late nineteenth-century origins through the Second World War. Making extensive use of archives in the United States, England, the Netherlands, Germany, and France, Lella Rupp examines the histories and accomplishments of three major transnational women's organizations to tell the story of women's struggle to construct a feminist international collective identity.

Rupp focuses on three major organizations that were, at least technically, open to all women: the broadly based and cautious International Council of Women, founded in 1888; the feminist International Alliance of Women, an offshoot of a group originally called the International Woman Suffrage Alliance, founded in 1904: and the vanguard Women's International League for Peace and Freedom, which grew out of the International Congress of Women that met at The Hague in 1915.