The federal government has been keeping tabs on foreign visitors to these shores for decades. In 1940 the Immigration and Naturalization Service began issuing each of them an Alien Registration number, and in 1944—in the midst of World War II—began to use this number to create individual case files called Alien Files or “A-Files.” They contain all records from any active case of an alien not yet naturalized—visas, photographs, applications, affidavits, and official correspondence—gathered as the individual passed through the U.S. immigration and inspection process. Archivist Elizabeth Burnes of the National Archives of Kansas City shows how the enterprising genealogist, biographer, or historian can access this treasure trove of information. The National Archives preserves and makes available to researchers more than 450,000 A-Files for individuals who were born in 1910 or earlier, many of them with direct connections to this area. Elizabeth Burnes works for the National Archives at Kansas City, located near historic Union Station, and serves as the lead archivist for “A-Files” reference. Her talk is part of Library’s monthly observance of Immigration Heritage Month. A progam of the Missouri Valley Special Collections, the Missouri Valley Sundays series is made possible in part by a grant from the National Endowment for the Humanities.