Former Owner
- Lathrop C. Harper, Inc.1
- Lathrop Colgate Harper1
- Laurence Kirby1
- Laurent Campagne1
- Legoué1
- Leo Olschki1
- Librairie Damascène Morgand1
- Libri, Edoardo, active 20th century1
- Lisa Norris Elkins1
- Long Island Historical Society, Maine1
- Louis Bourguet1
- Louis XIV of France1
- Lutheran Theological Seminary at Philadelphia1
- Lydia Thompson Morris1
- Maksymilian Mielzynski1
- Manuel John Johnson1
- Marcantonio V Borghese1
- Marchese Porri-Carcani1
- Margaret F. Woodward1
- Margaret Le Seigneur1