Encyclopedias, Almanacs, Transcripts, and Maps
- Locke, John (1631–1704)
- Lockhart, William B. (1906–1995)
- Lodge, Henry Cabot (1850–1924)
- Loewe v. Lawlor 208 U.S. 274 (1908)
- Long Haul-Short Haul Rate Discrimination
- Lopez v. United States 373 U.S. 427 (1963)
- López, United States v. 514 U.S. 549 (1995)
- Lord's Resistance Army (LRA)
- Loretto v. Teleprompter Manhattan Catv Corp. 458 U.S. 419 (1982)
- Louisiana Purchase Treaty (1803)
- Louisville Joint Stock Land Bank v. Radford 295 U.S. 555 (1935)
- Louisville, New Orleans & Texas Pacific Railway v. Mississippi 133 U.S. 587 (1890)
- Lovell v. City of Griffin 303 U.S. 444 (1938)
- Lovett, United States v. 328 U.S. 303 (1946)
- Loving v. Virginia 388 U.S. 1 (1967)
- Low-Value Speech
- Loyalist Volunteer Force (LVF)
- Loyalty Oath
- Loyalty-Security Programs
- Lucas v. South Carolina Coastal Council 505 U.S. 1003 (1992)