He also edited the English Advance and the Yiddish Fortschritt, the official publications of the Amalgamated Clothing Workers of America.

[3] In the 1904 United States House of Representatives election, Schlossberg was the Socialist Labor candidate in New York's 9th congressional district, losing to Democrat Henry M.

[8] A member of the radical left wing of the American socialist movement, Schlossberg fought with Joseph Barondess over leadership of the garment workers and broke with Morris Hillquit, Meyer London, and Abraham Cahan over socialist policies and tactics.

As its secretary-treasurer, he formed a successful 25-year team with president Sidney Hillman, administered its accounts, wrote books and pamphlets on the union's programs, and advocated social reform.

A prolific writer on labor, he wrote articles for the Yiddish and English press for forty years and in 1935 published a collection of essays called "The Workers and Their World."

[1] His daughter Ruth Landes was a professor of anthropology at McMaster University in Hamilton, Ontario, Canada.

[8] He was buried in Montefiore Cemetery's Jewish National Workers Alliance burial society section.