Union Depot

A factory floor devoted entirely to other people’s secrets, love letters and overdue bills. That’s what St. Paul’s Union Depot became during the 1940s, when 400 workers sorted as many as 50,000 mail bags a day while trains waited on the platforms to carry their contents across the country. It was America’s third-largest railway mail transfer station, behind only New York and Chicago.

Mail clerks sorted correspondence aboard moving trains, memorizing routes and preparing sacks to be transferred at precisely the right stop. The depot became one of the busiest links in that system, with more than 20 million pieces of mail passing through the station and neighboring post office each year. Architect Charles Sumner Frost designed the vast Neoclassical complex for efficiency as much as grandeur, incorporating nine platforms alongside a restaurant, drugstore, infirmary and playrooms for children.

Construction began in 1917 but was interrupted by World War I, leaving the depot unfinished until 1923. It replaced an earlier station that had burned in 1913 after once handling eight million passengers in a single year. When the last passenger train departed in 1971, the platforms fell quiet and postal operations claimed much of the concourse. After decades of uncertainty, Union Depot reopened as a transportation hub in 2012, once again sending passengers, packages and stories out into the world.