In 1933 Vladeck laid the groundwork for the Jewish Labor Committee, which was formed by Jewish trade unionists, socialists, and kindred groups and individuals to oppose the rise of Nazism in Germany. The JLC had its founding convention the following February, in New York's Lower East Side; Vladeck was the organization's president from the convention until his death. He, together with Jewish trade union leaders, successfully convinced the American Federation of Labor to support a national boycott of German goods at the labor federation's 1933 convention.