A 1926 report by Postmaster Charles J. Moos spurred a campaign in St. Paul, MN for a new federal building. "The Industrial and Civic Survey of St. Paul" documented a growing community with increasing manufacturing output and expanding postal operations. It included a map showing current federal agencies strewn throughout the city on twenty different sites. Together, these facts lead Moos and local business leaders to conclude that a central location to house these operations would greatly benefit the city and region. Their campaign paid off and Congress awarded funding for the new building in early 1927.
Project leaders then worked on acquiring a site in Lowertown St. Paul for to its close proximity to the new Union Depot and the Lower Landing docks on the Mississippi River. In 1931, the design process for the new Federal building began. Lambert Bassindale, whose recent work included the Union Depot, the Great Northern Depot (Mpls), and the Lowry Hotel, was chosen as the local architect. Holabird & Root, an architectural duo from Chicago, were selected at the associated architect. Their impressive portfolio included Soldier Field, the Chicago Daily News Building, and the Chicago Board of Trade.
The ground breaking for the new building occurred on April 11, 1932. The project was hit with a year-long-delay shortly thereafter, the result of the Depression and an overwhelmed Hoover Administration. Shortly after his inauguration, Roosevelt jump-started the project and construction proceeded steadily until its dedication on September 21, 1934 by Postmaster James A. Farley. At the dedication, Farley remarked that the new building was the most modern of its kind in the nation.
(The photo below shows the attendees of the dedication and the recreation of the photo on the day of its rededication in 2016.)
During its peak years after World War II, the building and the adjacent Union Depot were the third busiest Post Office operation in the nation with 2,000 employees working three shifts a day (or 6,000 people in total).
The building functioned as the City of Saint Paul's Main Post Office for 79 years. The last postal operations moved out in early 2013. That same year, the building was purchased for redevelopment and renamed Custom House.