Unbuilt
What is today Delta Airlines made the first air delivery between Minneapolis and Chicago in 1929. A rooftop hangar for air mail planes was planned for the main building but never added. The main building faced Pioneer Square park, which is now occupied by an apartment tower. A companion federal office building at a right angle to the post office on the park's western perimeter was suggested in 1934 but not built.
Read more about this topic: Minneapolis Post Office