| Date | Area | Territorial Acquisition | Includes | % Correct |
|---|---|---|---|---|
| 1803 | 827,987 | Louisiana Purchase | Louisiana, Arkansas, Missouri, Iowa, Minnesota, Oklahoma, Kansas, Nebraska, South Dakota, North Dakota, Colorado, Wyoming, Montana, Florida | 98%
|
| 1867 | 591,000 | Purchase of Alaska | Alaska | 93%
|
| 1848 | 529,189 | Mexican Cession | California, Nevada, Utah, Wyoming, Colorado, Arizona, New Mexico | 92%
|
| 1845 | 389,166 | Annexation of Texas | Texas, New Mexico, Colorado, Oklahoma, Kansas, Wyoming | 89%
|
| 1898 | 6,450 | Annexation of Hawaiian Islands | Hawaii | 84%
|
| 1783 | 892,135 | Thirteen States | Delaware, Pennsylvania, New Jersey, Georgia, Connecticut, Massachusetts, Maryland, South Carolina, New Hampshire, Virginia, New York, North Carolina, Rhode Island, Vermont, Kentucky, Tennessee, Ohio, Indiana, Mississippi, Illinois, Alabama, Maine, Michigan, Wisconsin, Minnesota, West Virginia | 84%
|
| 1846 | 286,541 | Oregon Territory | Oregon, Washington, Idaho, Montana, Wyoming | 77%
|
| 1819 | 72,101 | Florida | Florida | 73%
|
| 1898 | 3,508 | Puerto Rico | Puerto Rico | 71%
|
| 1854 | 29,670 | Gadsden Purchase | Arizona, New Mexico | 63%
|
| 1898 | 115,800 | Purchase of Philippine Islands | The Philippines | 53%
|
| 1818 | 46,194 | British Cession | Minnesota, North Dakota, South Dakota | 41%
|