- M. Barrows & company (Boston) (1)
- Malleable Iron Range Co (Beaver Dam, Wis, 1925) (1)
- Mc-Gill Warner Co (St. Paul, Minn) (1)
- McGill-Warner (St. Paul), 1925 (3)
- McGill-Warner Co (St. Paul, Minn), 1925 (1)
- Michigan Dept. of Conservation (Lansing, Mich) (1)
- Michigan Dept. of Conservation (Lansing, Mich) (1)
- Minneapolis (Minn.). City Planning Commission. (Minneapolis, Minn.?) (1)
- Minnesota Highway Department (St. Paul, Minnesota) (1)
- Minnesota Highway Dept. (St. Paul) (1)
- Minnesota State Board of Immigration : (St. Paul), 1925 (1)
- Moritz Ruhl (Leipzig) (2)