- 10 Leech, John, Mrs.
- 1 Leedom, Shaw & Stewart Philadelphia Carpet Mill
- 1 Leedom's Mill
- 2 Leeds, England
- 3 Lefferts, G.W. & Co. Worsted Yarn Mill
- 1 Leffler, Adam, 1805-1857
- 18 Legal documents
- 30 Legal literature
- 7 Legends (folk tales)
- 1 Legislating
- 1 Legislative acts
- 1 Legislative bodies
- 3 Legislative buildings
- 2 Legislators
- 1 Legs (animal components)
- 1 Lehigh (river)
- 37 Lehigh Avenue
- 2 Lehigh Avenue Branch
- 1 Lehigh Coal & Navigation Co.
- 8 Lehigh County, Pennsylvania
- 1 Lehigh Hosiery Co.
- 1 Lehigh Valley Railroad Co.
- 1 Lehigh, New York
- 7 Lehman (Firm)
- 1 Lehman, Frederick, Mrs.
- 1 Lehman, Peter, 1757-1823
- 9 Leicester Knitting Mills (Charles Spence & Co.) (Hosiery, knitted goods)
- 1 Leicester, England
- 1 Leinster, Augustus Frederick Fitzgerald, Duke of, 1791-1874
- 2 Leipzig, Germany
- 1 Leisenring, Luther Morris, 1875 - 1965, Architect
- 5 Leisure
- 3 Leithgow Street
- 2 LeMaistre, G.H.
- 2 Lemon Hill Drive
- 1 Lemon, Harry
- 69 Lemon, Mark, 1809-1870
- 2 Lemonade stands
- 12 Lenape, Pennsylvania
- 1 Lending