Dorr was briefly a member of the Socialist Party of America and lived on the Lower East Side of New York City, where she came into contract with the city's immigrant population and became acutely aware of the economic plight of the working class. Dorr's political activity included picketing for striking workers in the garment industry and working with the Women's Trade Union League on behalf of social legislation such as the minimum wage, the 8-hour day, and women's right to vote. Dorr's political efforts were instrumental on building the coalition of social reformers that forced the first major investigation by the U.S. Bureau of Labor into the conditions faced by female workers.