All - Constructed - 1910–1919
| La Frantz Apartments |
| Lahontan Dam and Power Station |
| Laird, Norton Company Building |
| Lake Andes Carnegie Library |
| Lake Toxaway Methodist Church |
| Lamar Building |
| Lamb, A.M., House |
| Langley, W. H., House |
| Lanterman House |
| La Porte City Station |
| Larrabee House |
| Larsen, Archie, House |
| Larson-Simonson House |
| Lassen County Court House |
| Lassen Hotel |
| Latta Arcade |
| Laurel Creek Covered Bridge |
| Lawrence County Courthouse |
| Lawson, Bamma Vickers, House |
| Lea, Henry C., School of Practice |
| Leavenworth Apartments |
| Leet, William A., and Frederick Hassler Farmstead District |
| Lehigh Valley Railroad Barge 79 |
| Leight, Valentine, General Store |
| LeMoine Building |
| Lemoine, Thomas A., House |
| Lena Road School |
| Leonard-Akin House |
| Levy, Soloman, House |
| Lewis, Harry and Molly, House |
| Lewis Mill |
| Liberty Theater |
| Libertyville High School Brainerd Building |
| Lichtstern House |
| Liederkranz |
| Lincoln Highway-Omaha to Elkhorn |
| Lincoln Hotel |
| Lincoln Statue |
| Linden |
| Linden Terrace |
| Linder, Roscoe Conklin, House |
| Lipp Barn |
| Lithuanian National Association Hall |
| Little, Arthur D., Inc., Building |
| Little Missouri Bank Building |
| Little Rock Confederate Memorial |
| Livingston, John and Daisy May, Ranch |
| Lodge Boleslav Jablonsky No. 219 |
| Lodgepole Opera House |
| Logan County Courthouse |
| Logan School |
| Logan, The |
| Logia Adelphia |
| Lone Beech |
| Longfellow School |
| Long Island School |
| Long Lake Hydroelectric Power Plant |
| Long View Stock Farm |
| Long, Willian H., House |
| Loomis-Parry House |
| Loon Lake Mountain Fire Observation Station |
| Lorain Fire Station No. 1 |
| Lorain Lighthouse |
| Loring House |
| Los Angeles Harbor Light Station |
| Los Burros Ranger Station |
| Love County Courthouse |
| Love County Jail and Sheriff's Residence |
| Lower Creek Road truss bridge over the Wickecheoke Creek |
| Luna County Courthouse and Park |
| Lund Grade School |
| Lutz, Robert, House |
| Lu Verne City Jail |
| Lyerly Building for Boys |
| Lynwood Pacific Electric Railway Depot |
| Lyric Theatre |
| M 95 (old)-Michigamme River Bridge |
| Mackenzie, Dr. K. A. J. and Cora, House |
| MacTavish House |
| Madisonville Town Hall |
| Maegly, A. H., House |
| Magma Hotel |
| Mahoney Building |
| Mahoning National Bank Building |
| Main Building of Dixie College |
| Maine, The |
| Main School |
| Majestic Hotel |
| Majestic Theater |
| Mallory Hotel |
| Manatee County Courthouse |
| Mancos Opera House |
| Mandan High School |
| Manges Cabin |
| Manhattan Bridge |
| Manion's General Store |
| Manistique East Breakwater Light |
| Mann, Anna Lewis, Old People's Home |
| Manthey Barn |
| Manti Carnegie Library |
Data from United States Park Service and Wikidata
