To dig the coal, the city began a concentrated effort to attract coal miners from other areas of the United States and from the coal-producing nations of Europe. Overseas, broadsides were distributed along the Mediterranean, promising prosperity in the coal fields of southeast Kansas. Steamship companies sent agents throughout Europe to recruit workers, underwriting one-way passage. From 1880 through 1915, huge waves of immigrants came to southeast Kansas. In all, over fifty nationalities came to mine coal and work in the area's smelters and other industries.