Fred P. Mann opened his first wholesale store in 1891 in Devils Lake, North Dakota. He initially sold only groceries, but later incorporated apparel and other general store items beginning in 1908. The business experienced early success due to Mann's effective advertising and his emphasis on salesmanship. Business volume ran to half a million dollars annually, which impressed business circles when considering that Devils Lake was a town of only 5,000 in the early 1900s.

Manns was incorporated on January 1, 1916. Fred P. Mann served as the first President of the Board of Directors; E. Earl Mann and Frank W. Mann were the other two original directors. In 1920, an amendment increased the Board of Directors to five members. Manns Inc. oversaw operation of the retail business and the renting of apartments and office space at 301-307 Fourth Street in Devils Lake. For the entirety of its operation, Manns Inc. was controlled by members of the Mann family on both the Board of Directors and Stockholders.

The business prospered until 1978 when attempts were made to revitalize the downtown area in order to compete with the mall on Highway 2. The Board of Directors was able to pay only the annual interest on its loans and the retail store suffered annual losses. Manns Inc. responded by raising the rent on its apartments and placing its assets into a higher-interest-yielding savings account. In March 1981 the Board of Directors adopted a motion admitting inquiries to liquidation of its assets. The retail business closed three months later, though ownership of the building remained with Manns Inc. By 1984 the corporation had become delinquent with the steam bills, bank note payments and Ramsey County property taxes. Manns Inc. ceased operation in 1985 and First National Bank assumed the firm's income.