All - Constructed - 1840–1849
| House at 68 Maple Street |
| House at 79-81 Salem Street |
| House at 95 Chestnut Street |
| House at 9 Linden Street |
| Houston, Sam, House |
| Hovey-Winn House |
| Howard-Odmin-Sherman Farmstead |
| Hubbard, Benjamin, House |
| Hughes-Clark House |
| Hughes, W. J., Business House |
| Huguenot Church |
| Huron Cemetery |
| Hutchinson-Blood House |
| Idlewild |
| Indiana School for the Deaf |
| Ingebretson, Gaute, Loft House |
| Institutional District |
| Iowa, Sac, and Fox Presbyterian Mission |
| Isom Place |
| Jarrell Plantation |
| Jarrett-Hayes House |
| Jefferson County Courthouse |
| Jenkins-Whelden Farmstead |
| Johnson County Courthouse |
| Johnson, Edwin C., House |
| Johnson, Samuel, House |
| Johnson, William, House |
| John Street Building No. 170-176 |
| John Street Methodist Church |
| Jones, Alpheus, House |
| Judge Bates House |
| Julien Incription Panel |
| Kahal Kadosh Beth Elohim Synagogue |
| Katie Plantation House |
| Kennedy, Frederick A., Jr., and Caroline Hewett, Farm |
| Kimbrough-Hehr House |
| Knoble, Joseph, Brewery |
| Koerner, Gustave, House |
| Lafayette County Courthouse |
| LaFollette, Robert M., House |
| La Mesilla Historic District |
| Lamm-Pollmiller Farmstead District |
| Landes, Samuel, House |
| Landry Tomb |
| Lane's Mill Historic Buildings |
| Lanier Mansion |
| Lanier, Sidney, Cottage |
| Lapeer County Courthouse |
| Lawn, The |
| Lawrence, Amos, House |
| Lay, Hiram, Cobblestone Farmhouse |
| L. C. Ranch Headquarters |
| LeBeuf Plantation House |
| Lee, S. D., House |
| Lefferts-Laidlaw House |
| Lentz House (Hotel Sheller) |
| Leonard, Chauncey B. House |
| Lexington Cemetery and Henry Clay Monument |
| Lie, Aslak, Cabin |
| Lincoln Park |
| Little River Light Station |
| Liverpool Cemetery |
| Livingston Homestead |
| Lloyd Street Synagogue |
| Lockington Covered Bridge |
| Lowell Cemetery |
| Lydia, The |
| Lyman School for Boys |
| MacDougal-Sullivan Gardens Historic District |
| Magnolia Hotel |
| Maidstone Manor Farm |
| Main Campus Complex, Roanoke College |
| Maine Woods Office |
| Main Street Friends Meeting House |
| Mansion House |
| Mariners' Church |
| Mariner's House |
| Mariner's Temple |
| Marsh, Alexander, House |
| Mathis House |
| Matthews Place |
| Maurice River Lighthouse |
| May, Asa, House |
| Mays Landing Presbyterian Church |
| May, Sophie, House |
| McAdory, Thomas, House |
| McCaffary, John, House |
| McElroy, John Wesley, House |
| McGavock-Gaines House |
| McKenzie, Monroe, House |
| McLaran, Charles, House |
| McPherson Town Historic District |
| Melrose |
| Melvin, Isaac, House |
| Merriam, Galen, House |
| Midway Plantation House and Outbuildings |
| Miller House |
| Miller House |
| Miller Plantation House |
| Milton House |
Data from United States Park Service and Wikidata
