L
- L-plan buildings (101)
- labor housing (142)
- labor unions (8)
- laboratories (112)
- laborers (24)
- lakes (5)
- lampposts (4)
- lanais (1)
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- land development (1)
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- landscape architects (2)
- landscapes (18)
- landscaping plans (1)
- lanterns (architecture) (1)
- lanterns (3)
- lateral sewers (1)
- Latin cross buildings (9)
- latrines (16)
- launch complexes (26)
- launching ramps (2)
- launchings (8)
- laundries (19)
- laundry rooms (2)
- laundry (19)
- law & legal affairs (13)
- law enforcement (60)
- law offices (24)
- lawn mowers (1)
- lead industry (1)
- lean-tos (10)
- leather industry (1)
- lecture halls (14)
- legislators (31)
- leisure (5)
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- libraries (rooms) (6)
- libraries (118)
- lifeboat stations (4)
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- lift locks (17)
- light stations (27)
- lighthouses (37)
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- Lincoln Highway (8)
- lintels (5)
- liveries (3)
- livestock loading chutes (1)
- livestock (9)
- living rooms (1)
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- locks (hardware) (1)
- locks (hydraulic facilities) (78)
- Locks (110)
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- lodges (54)
- lodging houses (53)
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- log buildings (225)
- log cabins (87)
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- lumber industry (15)
- lumber sheds (4)
- lumber (23)
- Lutheran churches (16)