Harris & Ewing, photographer · Public domain

A Lithuanian-born labor lawyer who represented the International Ladies' Garment Workers' Union during the 1910 Cloakmakers' strike, he became one of only two Socialist Party members ever elected to the U.S. Congress, representing New York's Lower East Side. His opposition to American entry into the First World War, and his refusal to bring a resolution supporting a Jewish state in Palestine, cost him political support and shortened his career.