1850 Atlas
| Name | What | Place | Pop | Other |
| Marion | T | Greene Co, PA | ||
| Marion | PT | Washington Co, ME | 270 | |
| Marion | PT | Wayne Co, NY | 1,839 | water by tributary of Mud Creek |
| Marion | PO | Franklin Co, PA | ||
| Marion | T | Centre Co, PA | 595 | |
| Marion | PT, CH | Marion Co, OH | 2,291 | seat of justice |
| Marion | T | Athens Co, OH | water by Federal & Wolf creeks | |
| Marion | T | Allen Co, OH | 1,046 | |
| Marion | T | Clinton Co, OH | 468 | |
| Marion | T | Fayette Co, OH | 841 | |
| Marion | T | Hancock Co, OH | 904 | |
| Marion | T | Hardin Co, OH | 452 | |
| Marion | T | Hocking Co, OH | 1,746 | |
| Marion | PT | Mercer Co, OH | 1,428 | |
| Marion | PT | Shelby Co, OH | ||
| Marion | T | Putnam Co, IN | 1,320 | |
| Marion | T | Shelby Co, IN | 786 | |
| Marion | PT | Livingston Co, MI | 883 | |
| Marion | V | Scott Co, KY | ||
| Marion | PO | Crittenden Co, KY | ||
| Marion | PV, CH | Smyth Co, VA | seat of justice, water by Middle fork of Holston river | |
| Marion | PV | McDowell Co, NC | ||
| Marion | PV, CH | Twiggs Co, GA | seat of justice | |
| Marion | PV, CH | Grant Co, IN | 703 | seat of justice, water by Missisinewa river |
| Marion | PV, CH | Williamson Co, IL | seat of justice | |
| Marion | PV, CH | Perry Co, AL | 1,544 | seat of justice |
| Marion | PV, CH | Lauderdale Co, MS | seat of justice, water by head branches of Oktibbeha creek | |
| Marion | PV | Cole Co, MO | water by Missouri river | |
| Marion | T | Buchanan Co, MO | 798 | |
| Marion | PV, CH | Linn Co, IA | seat of justice | |
| Marion | PV, CH | Crittendon Co, AR | seat of justice | |
| Marion | T | Union Co, AR | 169 | |
| Marion | T | White Co, AR | 404 | |
| Marion | T | Newton Co, MO | ||
| Marion | T | Livingston Co, MO | ||
| Marion | T | Polk Co, MO | ||
| Marion | T | Monroe Co, MO | ||
| Marion | T | Ray Co, MO | ||
| Marion | T | St Francis Co, MO | ||
| Marion | T | Saline Co, MO | ||
| Marion | T | Taney Co, MO | ||
| Marion | PO | Union parish, LA | ||
| Marion | PO | Angelina Co, TX | ||
| Marion | PV, CH | Marion dist, SC | seat of justice, water by Catfish creek | |
| Marion | PO | Hartford Co, CT | ||
| Marion | PO | Kenozha Co, WI | ||
| Marion City | PV | Marion Co, MO | water by Mississippi river | |
| Marion College | V | Marion Co, MO | seat of Marion College | |
| Marionsville | PO | Forest Co, PA | ||
| Mariposa | PO | Mariposa Co, CA | ||
| Marissa | PO | St Clair Co, IL | ||
| Marits | PO | Morrow Co, OH | ||
| Markesan | PO | Marquette Co, WI | ||
| Marksborough | PV | Warren Co, NJ | ||
| Marksville | PV | Page Co, VA | ||
| Marksville | PV, CH | Avoyelles parish, LA | ||
| Marlborough | PT | Cheshire Co, NH | 887 | water by tributaries of Ashuelot river |
| Marlborough | PT | Windham Co, VT | 896 | water by west branch of West river, Green river & Whetstone brook |
| Marlborough | PT | Middlesex Co, MA | 2,941 | water by tributary of Concord river |
| Marlborough | PT | Hartford Co, CT | 832 | |
| Marlborough | PT | Ulster Co, NY | 2,869 | water by Hudson river |
| Marlborough | PO | Monmouth Co, NJ | ||
| Marlborough | T | Montgomery Co, PA | 1,174 | water by Perkiomen & Swamp creeks |
| Marlborough | PT | Stark Co, OH | 2,133 | |
| Marlborough | T | Delaware Co, OH | 587 | |
| Marlborough | PO | Chester Co, PA | ||
| Marlbrook | PO | Hempstead Co, AR | ||
| Marley's Mills | PO | Randolph Co, NC | ||
| Marlin Bottom | PO | Pocahontas Co, VA | ||
| Marlow | PT | Cheshire Co, NH | 708 | water by Ashuelot river |
| Marlton | PO | Burlington Co, NJ | ||
| Marple | PO | Delaware Co, PA | 876 | |
| Marquette | PV, CH | Marquette Co, WI | water by Neenah river | |
| Marquette | PO | Marquette Co, MI | ||
| Marriottsville | PO | Anne Ardundel Co, MD | ||
| Marrowbone | PO | Cumberland Co, KY | ||
| Mars | PO | Bibb Co, AL | ||
| Mars | T | Posey Co, IN | 1,319 | |
| Mars Bluff | PO | Marion dist, SC | ||
| Marseilles | PV | Noble Co, IN | ||
| Marseilles | PV | LaSalle Co, IL | on the Grand Rapids of Illinois river, and Illinois & Michigan canals | |
| Marseilles | PO | Wyandott Co, OH | ||
| Marsh | PO | Chester Co, PA | ||
| Marshall | PT | Oneida Co, NY | 2,115 | water by Oriskany creek & Chenango canal |
| Marshall | PT, CH | Calhoun Co, MI | 2,822 | seat of justice, at the confluence of Kalamazoo river & Rice creek |
| Marshall | PT, CH | Clark Co, IL | 1,341 | seat of justice |
| Marshall | PO | Henry Co, IA | ||
| Marshall | PV, H | Saline Co, MO | ||
| Marshall | PV | Marshall Co, IN | ||
| Marshall | PO | Highland Co, OH | ||
| Marshall | PO | Bath Co, KY | ||
| Marshall | PO | Harrison Co, TX | ||
| Marshall's Creek | PO | Monroe Co, PA | ||
| Marshall's Ferry | PO | Grainger Co, TN | ||
| Marshallville | PV | Baughman's twp, Wayne Co, OH | ||
| Marshallville | PV | Macon Co, GA | ||
| Marshallton | PV | Chester Co, PA | ||
| Marshfield | PT | Washington Co, VT | 1,102 | water by Onion river |
| Marshfield | PT | Plymouth Co, MA | 1,837 | water by Massachusetts bay, North & South rivers |
| Marshfield | PO | Erie Co, PA | ||
| Marston's Mills | PO | Barnstable Co, MA |