"The Powell Square Building was constructed in 1916 as the headquarters for the John T. Milliken Pharmaceutical and Absorbent Cotton Plant. When Mr. Milliken died from pneumonia three years later, he was said to be the richest man in St. Louis. The buildings architect was William Wedemeyer, who's architectural firm is the predecessor of Wedemeyer-Cernick-Corrubia, which still operates today."
"In 1926, the building was purchased by the Fulton Bag and Cotton Mill Company. The transaction was unusual in that as part of Fulton Bag's payment for the building on Cedar, their former building at 12 South Seventh Street was transferred to Milliken Pharmaceutical, who moved into the building and remained for several years. The building on South Seventh still stands and was renovated several years as the Fulton Bag Lofts. Photo above ca. 1930 from the Georgia Institute of Technology."
"In 1952 Fulton Bag added the truck dock addition to the east side of the building, also completely constructed of formed concrete. in 1956, Fulton Bag moved to a new building constructed for the company on Gustine Avenue. General Fibre Company purchased the former Milliken plant in 1957 and occupied the building for several years. Between that time and 2001, the building had numerous owners/tenants, one of which was the Dan Powell Co. Inc., which gave the building its current name Powell Square."
All research credit goes to (and above text word for word copied from) Paul @: http://vanishingstl.blogspot.com/2013/01/city-burns-cash-and-opportunity-with.html