Noun
a political party in the United States; formed in 1874 to advocate the peaceful introduction of socialism
Source: WordNetIt predates Leninism as De Leonism's principles developed in the early 1890s with De Leon's assuming leadership of the Socialist Labor Party ; Leninism and its vanguard party idea took shape after the 1902 publication of Lenin's " What Is to Be Done? Source: Internet
The Socialist Labor Party of America found itself divided over the trade union policy as adopted at the 1896 National Convention, and by the brutal manner in which the party regulars maintained their influence. Source: Internet