1850 Atlas
| Name | What | Place | Pop | Other |
| Mandano | PO | Skeneateles twp, Onondaga Co, NY | ||
| Mandarin | PO | Duval Co, FL | water by St John's river | |
| Mandeville | PO | St Tammany parish, LA | water by Lake Pontchartrain | |
| Mangohick | PO | King William Co, VA | ||
| Manhasset | PV | North Hempstead twp, Queen's Co, Long Island, NY | water by Long Island sound | |
| Manhattan | PV | Port Lawrence twp, Lucas Co, OH | 541 | water by Maumee river & Lake Erie, at terminus of Wabash & Erie canal |
| Manhattan | PV | Putnam Co, IN | water by Eel river | |
| Manhattanville | PV, City | County of New York | Water by Hudson river | |
| Manheim | PT | Herkimer Co, NY | 1,902 | water by East Canada creek & Mohawk river |
| Manheim | PT | Lancaster Co, PA | 2,087 | water by Moravia, Great & Little Conestoga creeks |
| Manheim | T | York Co, PA | 1,806 | water by Hammer creek |
| Manheim Centre | PO | Manheim twp, Herkimer Co, NY | ||
| Manilla | PO | Rush Co, IN | ||
| Manistee (not listed) | (Manistee Co, MI) | (seat of justice, only 65 people in this county) | ||
| Manitoowoc | PV, CH | Manitoowoc Co, WI | seat of justice, water by Manitoowoc riber & Lake Michigan | |
| Manitoowoc Rapids | PO | Manitoowoc Co, WI | ||
| Manlius | PT | Onondaga Co, NY | 6,289 | water by Limestone & Chittenango creeks |
| Manlius | PT | Allegan Co, MI | 82 | |
| Manlius Centre | PV | Manlius twp, Onondaga Co, NY | on the Erie canal | |
| Manly | PO | Ashe Co, NC | ||
| Manlyville | PO | Henry Co, TN | ||
| Mannborough | PV | Amelia Co, VA | ||
| Manningham | PV | Butler Co, AL | ||
| Mannington | PO | Leon Co, FL | ||
| Mannington | T | Salem Co, NJ | 2,187 | water by Salem river & Mannington creek |
| Mann's Choice | PO | Bedford Co, PA | ||
| Mannsville | PV | Ellisburgh twp, Jefferson Co, NY | ||
| Manny | PV, CH | Sabine parish, LA | seat of justice | |
| Manor | PT | Lancaster Co, PA | 3,135 | water by Conestoga river |
| Manor Hill | PO | Schoharie Co, NY | ||
| Manor Hill | PO | Huntingdon Co, PA | ||
| Manorville | PO | Suffolk Co, Long Island, NY | ||
| Mansfield | T | Lamoille Co, VT | 1,016 | water by Waterbury & Brown's rivers |
| Mansfield | PT | Bristol Co, MA | 1,789 | water by tributaries of Taunton river |
| Mansfield | PT | Tolland Co, CT | 2,517 | water by Willimantic & Natchaug rivers |
| Mansfield | T | Cattaraugus Co, NY | 1,057 | water by Cattaraugus creek & tributaries of Alleghany river |
| Mansfield | PT | Warren Co, NJ | 1,617 | water by Muscibetecong & Pohatcong creeks |
| Mansfield | T | Burlington Co, NJ | 2,953 | water by Blakc's, Craft's & Assicunk creeks |
| Mansfield | PO | Tioga Co, PA | ||
| Mansfield | PV, CH | Richland Co, OH | 3,557 | seat of justice |
| Mansfield | PO | Louisa Co, VA | ||
| Mansfield | PC, CH | De Soto parish, LA | seat of justice | |
| Mansfield | PO | Henry Co, TN | ||
| Mansfield | PO | Kendall Co, IL | ||
| Mansfield Centre | PO | Mansfield twp, Tolland Co, CT | ||
| Mansfield Depot | PO | Tolland Co, CT | ||
| Mansker's Creek | PO | Davidson Co, TN | ||
| Mansura | PO | Avoyelles parish, LA | ||
| Manton | PO | Providence Co, RI | ||
| Manton | PO | Marion Co, KY | ||
| Mantua | PT | Portage Co, OH | 1,169 | water by Cayahoga river |
| Mantua | PV | McMinn Co, TN | ||
| Mantua | PO | Pickens Co, AL | ||
| Mantua Centre | PO | Mantua twp, Portage Co, OH | ||
| Manville | PO | Providence Co, RI | ||
| Manwaring's | PO | Shelby Co, IN | ||
| Maon | PO | Panola Co, MS | ||
| Maple | PT | Ionia CO, MI | ||
| Maple | PO | Brown Co, OH | ||
| Maple Creek | PO | Washington Co, PA | ||
| Maple Furnace | PO | Butler Co, PA | ||
| Maple Grove | PO | Butternuts twp, Otsego Co, NY | ||
| Maple Grove | PO | Barry Co, MI | ||
| Maple Grove | PO | Aroostook Co, ME | ||
| Maple Grove | PO | Knox Co, OH | ||
| Maple Hill | PO | Davidson Co, NC | ||
| Maple Springs | PO | Red River Co, TX | ||
| Maplesville | PV | Bibb Co, AL | ||
| Mapleton | PV | Abbeville dist, SC | ||
| Mapleton | PV | Stark Co, OH | ||
| Mapleton | PO | Niagara Co, NY | ||
| Mapleton | PO | Waukesha Co, WI | ||
| Mapletown | PT | Greene Co, PA | 864 | |
| Mapleville | PO | Providence Co, RI | ||
| Maquoketa | PO | Jackson Co, IA | ||
| Maquon | PO | Knox Co, IL | ||
| Maradosia | PO | Morgan Co, IL | ||
| Maramec | PO | Crawford Co, MO | at Big Springs of Maramec river | |
| Marathon | PT | Cortland Co, NY | 1,149 | water by Toughnioga river |
| Marathon | T | Lapeer Co, MI | 205 | |
| Marathon | PO | Clermont Co, OH | ||
| Marble | T | Hot Springs Co, AR | ||
| Marble Creek | PO | Jessamine Co, KY | ||
| Marble Dale | PO | Litchfield Co, CT | ||
| Marble Furnace | PO | Adams Co, OH | ||
| Marble Hall | PO | Hawkins Co, TN | ||
| Marble Hill | PO | Prince Edward Co, VA | ||
| Marble Hill | PO | Franklin Co, TN | ||
| Marblehead | PT | Essex Co, MA | 6,107 | water by Massachusetts bay |
| Marblehead | PO | Ottawa Co, OH | ||
| Marblehead | PO | Gilmer Co, GA | ||
| Marbletown | PT | Ulster Co, NY | 3,839 | water by Esopus & Rondout creeks, Delaware & Hudson rivers |
| Marburyville | V | St Tammany parish, LA | ||
| Marcelline | PO | Adams CO, IL | ||
| Marcellon | PO | Columbia Co, WI | ||
| Marcellus | PO | Washington Co, IA | ||
| Marcellus | PT | Onondaga Co, NY | 2,759 | water by Nine Mile creek |
| Marcellus Falls | PV | Marcellus twp, Onondaga Co, NY | water by Nine Mile creel | |
| Marchand | PO | Indiana Co, PA | ||
| Marcus | PO | Jackson Co, GA | ||
| Marcus Hook | PV | Lower Chichester twp, Delaware Co, PA | 492 | water by Delaware river |
| Marcy | PT | Oneida Co, NY | 1,857 | water by Nine Mile creek & Mohawl river |
| Marcy | PO | La Grange Co, IN | ||
| Marcy | PO | Waukesha Co, WI | ||
| Mardisville | PV | Talladega Co, AL | water by Talladega creek | |
| Marengo | PT | Calhoun Co, MI | 1,014 | |
| Marengo | PO | Galen twp, Wayne Co, NY | ||
| Marengo | PT | McHenry Co, IL | 1,0360 | water by Kishawaukie river |
| Marengo | PO | Iowa Co, IA | ||
| Marengo | PO | Morrow Co, OH | ||
| Marengo | PO | Laurens dist, SC | ||
| Margaretta | PT | Erie Co, OH | 1,537 | |
| Margaretta Furnce | PO | York Co, PA | ||
| Maria Creek | PO | Knox Co, IN | ||
| Maria Forge | PO | Talladega Co, AL | ||
| Maria Stein | PO | Mercer Co, OH | ||
| Mariana | PV, CH | Jackson Co, FL | seat of justice, water by Chipola river | |
| Mariaville | PT | Hancock Co, ME | 374 | water by Union river, now called Tilden |
| Mariaville | PO | Duanesburgh twp, Schenectady Co, NY | ||
| Maries | T | Gascinade Co, MO | ||
| Marietta | PO | Marcellus twp, Onondaga Co, NY | ||
| Marietta | PB | East Donegal twp, Lancaster Co, PA | 2,099 | water by Susquehanna river & Chiques creek |
| Marietta | PT, CH | Washington Co, OH | 4,244 | seat of justice, water by Muskingum & Ohio rivers, seat of Marietta Collegiate Institute |
| Marietta | PO | Fulton Co, IL | ||
| Marietta | PV, CH | Cobb Co, GA | seat of justice | |
| Marietta | PV | Shelby Co, IN | ||
| Marietta | PO | Itawamba Co, MS | ||
| Marine | PO | Madison Co, IL | ||
| Marine Mills | PO | St Croix Co, WI |