The Social Democratic Labor Party (SDLP) was a political party in Russia that emerged in the late 19th century, advocating for socialism and workers' rights. It played a crucial role in the political landscape leading up to the February Revolution of 1917, where it sought to represent the interests of the working class and promote democratic reforms. The party was characterized by its commitment to both socialism and democracy, which influenced many revolutionary movements during this transformative period in Russian history.