In the late 19th century, Pilsen was inhabited by German, Polish, Italian, and Czech immigrants. Czech immigrants were the most prominent and named the district after Plzeň, the fourth largest city in what is now the Czech Republic. They replaced the Germans and Irish who had settled there before them, in the mid-nineteenth century. These German and Irish residents lived in poor conditions throughout the 1850s and ‘60s. The Pilsen area was overcrowded and suffered from flooding, lack of indoor plumbing, and illness. A cholera outbreak that killed hundreds, eventually led the German and Irish residents to move in search of better living conditions. The population also included smaller numbers of other ethnic groups from the Austro-Hungarian Empire, such as Slovaks, Slovenes, Croats and Austrians, as well as immigrants of Polish and Lithuanian heritage. Many of the immigrants worked in the stockyards and surrounding factories. Like many early 20th century American urban neighborhoods, however, Pilsen was home to both wealthy professionals and the working class, with the whole area knitted together based on the ethnicities, mostly of Slavic descent, who were not readily welcome in other areas of the city.