The Seattle Section of the Socialist Labor Party (SLP) was founded in the early 1890's as a branch of the Socialist Labor Party of America. The SLP was founded as a Marxist political party in 1876, the first nationwide socialist party in the United States. The party promoted the doctrines of Daniel DeLeon, theorist of the SLP, which advocated a classless, stateless, industrial democracy in which private property would be abolished and all natural resources and means of production would be operated by the workers through Socialist Industrial Unions. The SLP planned to achieve its goals through national and local elections and by capturing the trade union movement. However, the party's narrow sectarian ideology, its insistence on doctrinal unity and party discipline, together with its rejection of social reform alienated it from the trade union movement. After modest success in the 1890s, the party declined and never numbered more than a few thousand. It survived however, and continued to run candidates for national and state office.

The Socialist Labor Party was the first socialist organization of any importance in the Pacific Northwest but it never established ties with the labor movement and never developed beyond a small cadre. During the period documented by these papers, 1930-1962, the Section frequently consisted of fewer than six active members and at times, particularly in the early 1950s, nearly ceased to exist. Section Seattle experienced frequent internal dissent, occasionally expelled members and was, in 1944, itself censured, expelled from the Party and reorganized. The business of the Section was carried on by an organizer who was democratically chosen and who reported to the secretary of the State Executive Committee. The State Executive Committee answered to the National Executive Committee which was headed by the National Secretary, an office held by Arnold Peterson throughout this period. The official organ of the Party was the , which the Section sold through subscriptions and newstands. Its other activities included the sale of SLP pamphlets, distribution of leaflets, lectures, classes and social activities. The SLP in Washington held an annual convention and also conventions to nominate candidates for state elections.