In this scholarly yet engaging book, the authors synthesize more than a decade of their historical research on U.S. immigration, dispelling myths and discerning patterns. They combine personal stories drawn from memoirs, secondary accounts, and other sources with careful data analysis. Abramitzky and Boustan helped pioneer the use of machine learning to link records and trace individuals across decennial population censuses and to harvest data from genealogical websites such as Ancestry.com. Putting these sources and methods to work, they establish that today’s immigrants to the United States continue to succeed economically to at least the same extent as those of earlier eras. Children of immigrants do even better economically than children of the native born. Immigrants erroneously seen as slow to assimilate (for instance, the Irish in the nineteenth century and Central Americans today) in fact assimilate the fastest. More surprising, immigrants rarely compete for jobs and success with native-born workers. They are a source of entrepreneurial and scientific talent that benefits the country as a whole. This evidence-based analysis leads the authors to recommend less restrictive immigration policies.