1850 Atlas
| Name | What | Place | Pop | Other |
| Uchee | PV | Russell Co, AL | ||
| Uchee Anna | PV, CH | Walton Co, FL | seat of justice, water by tributary of Choctawhatchie river | |
| Udina | PO | Kane Co, IL | ||
| Uffington | PO | Monongalia Co, VA | ||
| Uhlersville | PO | Northampton Co, PA | ||
| Uhricksville | PO | Mill twp, Tuscarawas Co, OH | ||
| Ulao | PO | Washington Co, WI | ||
| Uster | V | Ulster Co, NY | (see Saugerties) | |
| Ulster | PT | Bradford Co, PA | 1,082 | water by Susquehanna river |
| Ulsterville | PO | Shawangunk twp, Ulster Co, NY | ||
| Ultima Thule | PV | Sevier Co, AR | water by tributary of Little river | |
| Ulysses | PT | Tompkins Co, NY | 3,122 | water by Cayuga lake |
| Ulysses | PT | Potter Co, PA | 6898 | |
| Umcolcus | PO | Aroostook Co, ME | ` | |
| Unadilla | PT | Otsego Co, NY | 2,463 | water by Unadilla & Susquehanna rivers |
| Unadilla | PT | Livingston Co, MI | 1,027 | water by Portage river |
| Unadilla Centre | PO | Unadilla twp, Otsego Co, NY | ||
| Unadilla Forks | PV | Plainfield twp, Otsego Co, NY | at the confluence of east & west branches of Unadilla river | |
| Uncasville | PV | Montville twp, New London Co, CT | on the reservation of the Mohegan Indians | |
| Underhill | PT | Chittenden Co, VT | 1,599 | water by head waters of Brown river |
| Underhill Centre | PO | Chittenden Co, VT | ||
| Underwood | PO | Hopkins Co, KY | ||
| Underwoods | PO | Marion Co, OH | ||
| Union | PT | Lincoln Co, ME | 1,972 | water by St George & Muscongus rivers |
| Union | PO | Carroll Co, NH | ||
| Union | PT | Tolland Co, CT | 728 | water by Quinnebaug river |
| Union | PT | Broome Co, NY | 2,143 | water by Susquehanna river |
| Union | PT | Essex Co, NJ | 1,662 | water by Elizabeth & Rahway rivers |
| Union | PT | Erie Co, PA | 1,095 | |
| Union | PT | Huntingdon Co, PA | 631 | |
| Union | PT | Bedford Co, PA | 1,291 | |
| Union | PT | Luzerne Co, PA | 1,308 | water by Susquehanna river |
| Union | PT | Washington Co, PA | 1,192 | |
| Union | PT | Mifflin Co, PA | 1,284 | |
| Union | PT | Fayette Co, PA | 2,333 | water by Redstone creek |
| Union | PT | Schuylkill Co, PA | 1,064 | |
| Union | T | Tioga Co, PA | 825 | |
| Union | PT | Union Co, PA | 1,452 | water by Susquehanna river |
| Union | PO | York Co, PA | ||
| Union | PV, CH | Monroe Co, VA | 377 | seat of justice |
| Union | PV | Randolph twp, Montgomery Co, OH | ||
| Union | T | Auglaize Co, OH | 2,020 | |
| Union | PT | Belmont Co, OH | 1,872 | water by Stillwater creek |
| Union | T | Brown Co, OH | 4,379 | water by Ohio river, Red Oak & Eagle creeks |
| Union | T | Carroll Co, OH | 804 | |
| Union | T | Butler Co, OH | 2,173 | |
| Union | T | Champaign Co, OH | 1,646 | |
| Union | T | Clermont Co, OH | ||
| Union | T | Clinton Co, OH | 2,320 | |
| Union | T | Hancock Co, OH | 1,150 | |
| Union | T | Highland Co, OH | 1,408 | |
| Union | T | Knox CO, OH | 1,192 | water by Mohiccan river |
| Union | T | Lafayette Co, OH | ||
| Union | T | Lawrence Co, OH | 1,318 | |
| Union | T | Licking Co, OH | 2,368 | |
| Union | T | Logan Co, OH | 804 | |
| Union | T | Madison Co, OH | 1,647 | |
| Union | T | Mercer Co, OH | 746 | |
| Union | T | Miami Co, OH | 2,227 | |
| Union | T | Monroe Co, OH | 1,930 | |
| Union | T | Morgan Co, OH | 1,795 | |
| Union | T | Muskingum Co, OH | 901 | |
| Union | T | Putnam Co, OH | 515 | |
| Union | T | Scioto Co, OH | 1,105 | water by Little Scioto river |
| Union | T | Tuscarawas Co, OH | 994 | |
| Union | T | Ross Co, OH | 2,666 | |
| Union | T | Union Co, OH | 994 | |
| Union | T | Warren Co, OH | 722 | |
| Union | T | Washington Co, OH | 1,165 | |
| Union | V | Boone CO, KY | ||
| Union | T | Branch Co, MI | 1,271 | |
| Union | PV | Cass Co, MI | ||
| Union | PO | Rock Co, WI | ||
| Union | T | Cape Girardeau Co, MO | ||
| Union | T | Washington Co, MO | 1,761 | |
| Union | T | Randolph Co, MO | 504 | |
| Union | T | Marion Co, MO | 1,107 | |
| Union | T | Monroe CO, MO | ||
| Union | T | St Genevieve Co, MO | 898 | |
| Union | T | Saline Co, MO | ||
| Union | PV | Greene Co, AL | ||
| Union | PV | Newton Co, MS | ||
| Union | T | Grant Co, IN | 544 | |
| Union | T | Hancock Co, IN | 522 | |
| Union | PT | Miami Co, IN | 812 | |
| Union | PT | Rush Co, IN | ||
| Union | PT | Shelby Co, IN | 1,071 | |
| Union | PT | Montgomery Co, IN | 5,627 | |
| Union | PV | Franklin Co, MO | water by Bourdeuse creek | |
| Union | T | Johnson Co, AR | ||
| Union | T | Fulton Co, AR | 363 | |
| Union | T | Lawrence Co, AR | 530 | |
| Union | T | Izard Co, AR | 466 | |
| Union | T | Pope Co, AR | ||
| Union | PT | St Francis Co, AR | ||
| Union | T | Van Buren Co, AR | ||
| Union | PO | Pike Co, IN | ||
| Union | PO | Van Buren Co, IA | ||
| Union | PO | Washington Co, NC | ||
| Union | PO | Jasper Co, TX | ||
| Union | PO | Santa Clara Co, CA | ||
| Union and Perry | PT | Vannderburgh Co, IN | ||
| Union Bridge | PO | Carroll Co, MD | ||
| Union Bride | PO | Titus Co, TX | ||
| Union Centre | PO | Union twp, Broome Co, NY | ||
| Union Centre | PO | Miami Co, IN | ||
| Union City | PO | Randolph Co, IN | ||
| Union City | PV | Sherwood twp, Branch Co, MI | water by St Joseph's river at head of navigation | |
| Union Church | PO | Jefferson Co, MO | ||
| Union Corners | PO | Sparta twp, Livingston Co, NY | ||
| Union Corners | PO | Van Buren Co, IA | ||
| Union District | PO | Washtenaw Co, MI | ||
| Union Falls | PV | Black Brook twp, Clinton Co, NY | water by Saranac river | |
| Union Furnace | PO | Huntingdon Co, PA | ||
| Union Furnace | PO | Patrick Co, VA | ||
| Union Grove | PO | Prince George Co, VA | ||
| Union Grove | PO | Whiteside Co, IL | ||
| Union Grove | PO | Racine Co, WI | ||
| Union Hall | PO | Franklin Co, VA | water by Pig river | |
| Union Level | PO | Mecklenburgh Co, VA | ||
| Union Line | PO | Spartansburgh dist, SC | ||
| Union Meeting House | PO | Baltimore Co, MD | ||
| Union Mills | PV | Broadalbin twp, Fulton Co, NY | ||
| Union Mills | PV | Union twp, Erie Co, PA | water by tributary of French creek | |
| Union Mills | PV | Carroll Co, MD | ||
| Union Mills | PV | Fluvanna Co, VA | water by Rivanna river | |
| Union Mills | PO | Heard Co, GA | ||
| Union Mills | PO | La Porte Co, IN | ||
| Union Mills | PO | Mahaska Co, IA | ||
| Union Plain | PO | Brown Co, OH | ||
| Union Point | PO | Greene Co, GA | ||
| Union Point | PO | Concordia parish, LA | ||
| Union Point | PO | Union Co, IL | ||
| Union Prairie | PO | Allemarkee Co, IA | ||
| Union Settlement | PO | Oswego Co, NY | ||
| Union Society | PO | Windham twp, Greene Co, NY | ||
| Union Springs | PV | Springport twp, Cayuga Co, NY | water by Cayuga lake | |
| Union Springs | PV | Macon Co, AL | ||
| Union Springs | PO | Harrison Co, TX | ||
| Union Square | PV | Montgomery Co, PA | ||
| Union Square | PO | Mexico twp, Oswego Co, NY | ||
| Union Vale | PT | Dutchess Co, NY | 1,552 | |
| Union Valley | PO | Cortland Co, NY | ||
| Union Village | PV | Orange Co, VT | ||
| Union Village | V | Warren Co, OH | 722 | |
| Union Village | PO | Lisle twp, Broome Co, NY | ||
| Union Village | PV | Northumberland Co, VA | ||
| Union Village | V | Greenwich twp, Washington Co, NY | water by Batten kill |