After the devastating cholera epidemic in Hamburg in 1892, which allegedly brought in Russian emigrants, transit migration from Eastern Europe was reorganised. Since 1893, the American authorities demanded disinfection and several days of quarantine of all Russian migrants in the European port of departure. After negotiations with the Prussian government, the two German shipping lines Norddeutscher Lloyd (NDL) and Hapag succeeded in completely taking over and thus privatizing the previously deficient controls at the eastern border and the medical surveillance as well as the entire transport to the emigrant ports. They benefited from the central location of the Empire, which Eastern Europeans had to cross on their way to the North Sea ports. At the most important level crossings between Russia and Prussia, Hapag and NDL opened "control stations". There, all immigrants had to undergo disinfection and inspection in accordance with the provisions of American immigration laws. The model was the Ruhleben emigration station near Berlin, which had been in existence since 1891, with the procedures used there. Whoever failed the medical examination was sent back.