- Marching bands--United States.1
- Maria Jose, Queen, consort of Humbert II, King of Italy, 1906-2001.1
- Mathematics.1
- May celebrations.1
- Mayors--Chicago.1
- Maypoles.1
- McAdoo, W. G. (William Gibbs), 1863-1941.1
- McCarthy, Joe (Joseph), 1887-1978.1
- McCormick, Robert Rutherford, 1880-1955.1
- McGuire, Mickey.1
- Meat industry and trade.1
- Meat.1
- Medical personnel.1
- Medicine.1
- Mentally ill.1
- Metal-workers.1
- Meteorology.1
- Middle West Utilities Company.1
- Military ceremonies, honors, and salutes--United States.1
- Milk.1