The United States Census of 1880, conducted during June 1880, determined the resident population of the United States to be 50,189,209 - an increase of 30.2 percent over the 1870 Census.<br><br>The 1880 census contains records of families living in the United States and its territories during the latter half of the Great Westward Migration. Thirty-eight states were included in the 1880 census, plus the territories of: Arizona, Dakota, Idaho, Montana, New Mexico, Utah, Washington, and Wyoming. Non-organized Alaska was also enumerated, but the "Indian Territory" (now Oklahoma) was not enumerated for non-Indians.<br><br>聯邦普查員記錄當天關於每戶每個人的信息。調查人員可能於較後日期登門看訪，但他收集的信息應該是關於普查當日在家的人。基本普查查點單位是縣。每個縣被分為幾個計數區，每個計數區由一位計數員負責。填妥的表格被發送到華盛頓商務部的人口普查辦公室。<br><br>聯邦人口普查通常是可靠的，依靠線人的知識和普查員的細心。資料可能已經由任何一個家庭成員或鄰居給普查員。有些信息可能不正確，或者故意偽造。
