The Schlotterbeck & Foss Building at 117 Preble Street in Portland, Maine is significant for its association with the pharmaceutical and food processing industry on the local level between 1927 and 1966; and as a rare surviving industrial building by Maine?s most-noted architect John Calvin Stevens and a rare example of the Art Deco style of architecture in Portland. The less-well-known Portland architectural and engineering firm Webster & Libby played an important role in designing the building. The building was constructed for the food processing and pharmaceutical manufacturing operations of the Schlotterbeck & Foss company and continued in that use by the same company until 2015. The period of significance extends from the year of the building?s completion until fifty years before the present. Throughout that period, the building remained largely unchanged and continued in the same use by the same company.