- 12 Lenape, Pennsylvania
- 1 Lending
- 1 Lennig Chemical Works see Tacony Chemical Works
- 1 Lenoir & Forster
- 3 Lent
- 2 Lenz, David
- 3 Leo symbols
- 1 Leonard, Hubert Benjamin (Dutch), 1892–1952
- 5 Leopards
- 1 Leper colonies
- 1 Leprechauns
- 1 Leroy W. Fairchild & Co.
- 2 Lesage & Paignard
- 1 Leslie, Charles Robert, 1794-1859
- 1 Leslie, Malachi (Max) G., 1864-1933
- 2 Letter carriers
- 1 Letter carriers
- 1 Letter openers
- 1 Lettering
- 14 Letterpress printing
- 96 Letters (correspondence)
- 2 Letters of advice
- 1 Level (tools)
- 6 Lever Brothers Ltd.
- 1 Lever, Charles James, 1806-1872
- 1 Levering Academy
- 5 Leverington Avenue
- 1 Leverington Cemetery
- 4 Leverington Hotel
- 1 Levis' Mill
- 1 Lewis & Clark Exposition
- 2 Lewis' Cotton Factory
- 1 Lewis, Edmund Darch, 1835-1910
- 1 Lewis, John L. (John Llewellyn), 1880-1969
- 1 Lewis, Morgan (1754-1844)
- 1 Lewis, William David, 1792-1881
- 2 Lewisburg, Pennsylvania
- 1 LGBT
- 3 Liars
- 3 Libel & slander
