History of the League began with the work of the National American Women Suffrage Association, the group which led the 72-year drive for women's voting rights. The League was established in 1920 to help the nearly 20 million newly enfranchised women carry out their new responsibilities. Although women won the right to vote in Washington state in 1910, it was nine years before the 19th Amendment to the U.S. Constitution extended the vote to all the nation's women.

In the early days, The League of Women Voters of Washington supported state legislation pertaining to protection of children in fields of labor, health and education. League celebrated its 80th Anniversary in 2000.

The League of Women Voters of Snohomish County was formed in 1968 through the consolidation of the Leagues that had formed in South Snohomish County and in Everett in the late 1950s. Prior to 1968, the program focus of the two Leagues was the structure of local government.

Before becoming the League of Women Voters of Snohomish County, LWVSC went through several name changes. In 1957, the LWV of Mountlake Terrace began as a provisional League and subsequently became an official League in 1958. In 1959, it became the League of Women Voters of Snohomish County. In 1966, the League of Women Voters of Everett disbanded after having been a League since 1960 and joined the South County League. At the annual meeting in 1968, it then became the League of Women Voters of Snohomish County.

A Know Your County booklet was published in 1966 by the Everett and South Snohomish County Leagues. That publication has been updated periodically and thousands of copies distributed. It remains the sentinel citizen's guide to Snohomish County government. (Read it online.)

A League study of county government led to the conclusion that the space for jail facilities and county government operations was inadequate. A concurrent study on juvenile services found that those services were also inadequate. As a result, in 1964 the League supported a $4.5 million county bond issue proposition to finance an addition to the county courthouse and a youth detention center. The bond issue passed and those facilities were constructed.

Further study of county government led to the adoption of a League position favoring home rule for Snohomish County. Two league members served on the Home Rule Charter Commission. However, the proposed charter was defeated at the polls in 1968. A home rule charter was adopted eleven years later and became effective in 1980.

Other positions that were reached after study in the 1960s include support for enforcement of election laws and procedures, support for regional comprehensive planning, and park acquisition.

In recent years, studies have been performed and positions adopted on a range of local issues, including the following:

• Growth Management
• Solid Waste Management
• Health Care
• Mental Health Care
• Homelessness and Housing
• Formation of New Counties

The League of Women Voters of Washington subsequently adopted LWVSC's positions on health care and the formation of new counties.