"United States" . . "États-Unis" . . "Geographical Exploration and Mapping in the 19Th Century - a Survey of the Records in the National Archives" . . . . "Geographical exploration and mapping in the 19th century : a survey of the records in the National Archives"@en . "Geographical exploration and mapping in the 19th century : a survey of the records in the National Archives" . . . . "Sources" . . . . "History"@en . "History" . . . . . . . . "Bibliography"@en . . "Bibliography" . "United States. National Archives and Records Service." . . . .