On February 14, 1920 - six months before the 19th amendment to the Constitution was ratified - the League was formally organized in Chicago as the national League of Women Voters. Maud Wood Park became the first national president of the League. She had steered the women's suffrage amendment through Congress in the last two years before ratification.

The League was formed to help women carry out their new responsibilities as voters and to encourage them to use their new power to participate in shaping public policy. From the very beginning, however, it was apparent that the legislative goals of the League were not exclusively focused on women's issues and that citizen education aimed at all of the electorate was in order.

The League of Women Voters has continued to be an activist, grassroots organization whose leaders believe that citizens should play a critical role in advocacy. It was then, and is now, a nonpartisan organization. League founders believed that maintaining a nonpartisan status would protect the fledgling organization from becoming mired in the party politics of the day. However, League members were encouraged to be political themselves, by educating citizens about, and lobbying for, government and social reform legislation.

Since its inception, the League has helped millions of women and men become informed participants in government.

The League of Women Voters of Oshkosh was founded in 1920 by Jessie Jack Hooper, the first president of both LWV Wisconsin and LWV Oshkosh. The League of Women Voters of Neenah and Menasha and the League of Women Voters of Oshkosh merged in 2009 to form the LWV of Winnebago County.