The recording of ships' passenger lists was not required by law until 1819, and prior to that date only scattered lists of immigrants are thought to exist--until now, that is, for we have in this publication a record of thousands of British immigrants who arrived in the United States mainly between 1790 and 1812 and who had not yet been naturalized, and concerning whom few other records can be found. This is an altogether new and invaluable list of immigrants, founded upon a major record source few genealogists are aware of--the returns of aliens residing in the United States during the War of 1812. As of July 1812 British aliens in the United States were required to submit a report of "the persons composing their families, the places of their residence and their occupations or pursuits." These reports, or returns of the reports, upon which this work is based, normally give the name of the alien, aged fourteen or more, years of residence in the United States, number of persons in the family, place of residence, and occupation. In this compilation the aliens are listed in alphabetical order under their respective states, with accompanying data incorporated in the listing. In this manner as many as 12,000 or more aliens are identified, all of whom, for the reader's convenience, are again cited in the index.