Different groups of immigrants have employed chain migration among the different strategies used to enter, work, and live in the various republics of the Americas throughout their history. Social networks for migration are universal and not limited to specific nations, cultures, or crises. One group of immigrants to the British colonies in North America (and later the United States) was African slaves brought over forcibly; the circumstances of their migration do not fit the criteria of chain migration of free labor. Other groups, such as Germans fleeing chaos in Europe in the mid-1800s, Irish fleeing famine in Ireland in the same years, Eastern European Jews who emigrated from the Russian and Austro-Hungarian Empires in the late 1800s and early 1900s, and Italians and Japanese escaping poverty and seeking better economic conditions in the same period, did use chain migration strategies extensively, with resulting "colonies" of immigrants from the same villages, towns, and cities settling in enclaves in such cities as Boston, New York, São Paulo, Rio de Janeiro, Buenos Aires, Toronto, Montreal, Sydney, Melbourne, Auckland and Havana from the mid-1800s through the mid-1900s.