1850 Atlas
| Name | What | Place | Pop | Other |
| Magazine | T | Yell Co, AR | 571 | |
| Magnolia | PO | Chautauque twp, Chatauauque Co, NY | ||
| Magnolia | PO | Harford Co, MD | ||
| Magnolia | PO | Washington Co, VA | ||
| Magnolia | PO | Stark Co, OH | ||
| Magnolia | PO | Putnam Co, IL | ||
| Magnolia | PO | Rock Co, WI | ||
| Magnolia | PO | Crawford Co, IN | ||
| Magnolia | PO | Anderson Co, TX | ||
| Magnolia | PO | La Rue Co, KY | ||
| Magnolia Springs | PO | Jasper Co, TX | ||
| Mahala | PO | Adams Co, OH | ||
| Mahony | PO | Northumberland Co, PA | ||
| Mahomet | PO | Champaign Co, IL | ||
| Mahoning | T | Montour Co, PA | ||
| Mahoning | T | Carbon Co, PA | 1,521 | water by Susquehanna river & Mahoning creek |
| Mahoning | PT | Lawrence Co, PA | 1,841 | water by Great & Little Mahoning creeks |
| Mahoning | PO | Stark Co, OH | ||
| Mahopac | PO | Oakland Co, MI | ||
| Mahopak | PO | Carmel twp, Putnam Co, NY | near Mahopak lake | |
| Maiden Creek | PT | Berks Co, PA | water by Schuylkill river & Maiden creek | |
| Maiden Spring | PO | Tazewell Co, VA | ||
| Maidston | PT | Essex Co, VT | ||
| Maine | PV | Union twp, Broome Co, NY | ||
| Maine | PO | Cook Co, IL | ||
| Mainesburgh | PO | Tioga Co, PA | ||
| Maineville | PO | Columbia Co, PA | ||
| Malaga | PT | Monroe Co, OH | 1,561 | |
| Malaga | PV | Gloucester Co, NJ | water by branch of Maurice river | |
| Malcolm | PO | Jefferson Co, MS | ||
| Malden | PT | Middlesex Co, MS | 3,520 | water by Mystic river |
| Malden | PV | Saugerties twp, Ulster Co, NY | water by Hudson river | |
| Malden Bridge | PV | Chatham twp, Columbia Co, NY | water by Kinderhook creek | |
| Mallet Creek | PO | Medina Co, OH | ||
| Mallorysville | PV | Wilkes Co, GA | ||
| Malone | PT, CH | Franklin Co, NY | 4,550 | seat of justice, water by Salmon & Trout rivers |
| Malta | PT | Saratoga Co, NY | 1,349 | water by Anthony's Kill |
| Malta | PV | Morgan Co, OH | 2,308 | water by Muskingum river |
| Maltaville | PV | Malta twp, Saratoga Co, NY | near Round lake | |
| Malugan Grove | PO | Lee Co, IL | ||
| Malvern | PO | Carroll Co, OH | ||
| Mamakating | PT | Sullivan Co, NY | 4,107 | water by Bushe's kill, Delaware & Hudson canals |
| Mamaroneck | PT | Westchester Co, NY | 928 | water by Mamaroneck creek & Long Island sound |
| Mammelle | T | Poinsett Co, AR | ||
| Mammoth Cave | PO | Edmonson Co, KY | near Green river, at the great cavern of the same name celebrated for its extent & depth, and as affording a healthy subterranean climate for invalids | |
| Manack | PO | Lowndes Co, AL | ||
| Manahawkin | PV | Stafford twp, Ocean Co, NJ | water by Manahawkin creek | |
| Manalapan | PO | Monmouth Co, NJ | ||
| Manasquam | PV | Howell twp, Monmouth Co, NY | water by Mamasquam river | |
| Manatawny | PO | Berks Co, PA | ||
| Manatee | PO | Hillsborough Co, FL | ||
| Manayunk | PV | Roxborough twp, Philadelphia Co, PA | 6,158 | water by Schuylkill river & Flat Rock canal |
| Manchac | PV | East Baton Rouge parish, LA | water by Mississippi river | |
| Manchac House | PO | Travis Co, TX | ||
| Manchaug | PO | Worcester Co, MA | ||
| Manchester | PT, city | Hillsborough Co, NH | 13,932 | on east bank of Merrimack river |
| Manchester | PV, CH | Bennington Co, VT | 1,782 | seat of justice together with Bennington, water by Battenkill river |
| Manchester | PT | Essex Co, MA | 1,638 | water by Massachusetts bay |
| Manchester | PT | Hartford Co, CT | 2,546 | water by Hocbanum river |
| Manchester | PT | Ontario Co, NY | 2,940 | water by Canandaigua outlet |
| Manchester | V | Kirkland twp, Oneida Co, NY | water by Oriskany creek | |
| Manchester | T | Wayne Co, PA | 749 | |
| Manchester | PO | Ocean Co, NJ | ||
| Manchester | T | Passaic Co, NJ | 2,781 | water by Ramapo, Pompton & Passaic rivers |
| Manchester | PT | York Co, PA | 2,603 | |
| Manchester | PV | Carroll Co, MD | 507 | |
| Manchester | PV | Sprigg twp, Adams Co, OH | water by Ohio river | |
| Manchester | T | Morgan Co, OH | 1,337 | |
| Manchester | V | Franklin twp, Summit Co, OH | ||
| Manchester | PV | Chesterfield Co, VA | water by James river | |
| Manchester | PV, CH | Clay Co, KY | seat of justice, water by Goose creek | |
| Manchester | PT | Washtenaw Co, MI | 1,275 | |
| Manchester | T | Clark Co, AR | ||
| Manchester | PT | Dearborn Co, IN | 2,748 | |
| Manchester | PV | Scott Co, IL | ||
| Manchester | PV | St Louis Co, MO | ||
| Manchester | PV, CH | Coffee Co, TN | seat of justice, water by head branches of Duck river | |
| Manchester | PO | Sumter dist, SC | ||
| Manchester Bridge | PO | Poughkeepsoe twp, Dutchess Co, NY | water by Wappinger's creek | |
| Manchester Centre | PO | Manchester twp, Ontario Co, NY | ||
| Manchester Station | PO | Hartford Co, CT |