After a pause in European immigration during the U.S. Civil War, more than 20 million immigrants arrived, primarily from Southern and Eastern Europe, between 1880 and 1920. Because of the fluid borders of nations during the nineteenth century in Eastern Europe, it is difficult to provide accurate immigration nationality counts. In general, Southern European immigrants were motivated by economic opportunity, while Eastern Europeans, primarily Jews, fled religious persecution. World War I slowed immigration altogether, and the national-origin quotas established in 1921 and 1924 gave priority to Western and Northern Europeans. The collapse of the Soviet Union in the early 1990s resulted in the most recent wave of European immigration. Of all Jewish immigrants to the U.S. from the 1880s to 1925, nearly half were women. The majority of the more than two million Jews from the Russian Empire, Romania, and Austria-Hungary who entered the U.S before rigid quotas were in place, settled in crowded East Coast cities. Many worked in the burgeoning garment industry. According to Roger Daniels, in Coming to America, among the peoples who emigrated from Eastern Europe in the late nineteenth and early twentieth centuries were: Albanians, Byelorussians, Bosnian Muslims, Bulgarians, Cossacks, Croats, Czechs, Estonians, Finns, Georgians, Gypsies, Hungarians, Lithuanians, Macedonians, North Caucasians, Poles, Romanians, Russians, Serbs, Slovaks, Slovenes, and Ukrainians.