Columbia subject headings:
Poland--Emigration and immigration.
Polish people--United States--History--19th century.
United States--Emigration and immigration.
Working class--United States.
Harvard subject headings:
Poland--Emigration and immigration
Polish people--United States--History--19th century.
United States--Emigration and immigration.
Working class--United States
Princeton subject headings:
Poland--History--1864-1918.
Polish people--United States--History.