- Monticello Female Institute (Fairfield County, S.C.)1
- Morgan, Philip Hugh1
- Morgan, Philip Hugh, 1890-19841
- Morgan, William C.1
- Morrison, John D.1
- Morse, A. A.1
- Morse, Cyrus1
- Moseley, Elise1
- Moses, Jr., Franklin J.1
- Mount Vernon Ladies' Association of the Union1
- Mt. Pleasant and Sullivan's Island Ferry Company County (S.C.)1
- Murchinson, Collin Campbell1
- Music Teachers National Association1
- NOW National Action Center1
- Nagel and Mr. Dempster1
- Nance, Fredk. A.1
- National Advisory Committee on Farm Labor1
- National Association for American Composers and Conductors1
- National Council of Churches1
- National Freedmen's Relief Association1