A new post office building for Waterloo was originally improved in 1969, as U.S. Postal Service officials looked to move from an aging three-story facility, which has since been renovated and repurposed as the Waterloo Public Library. The original plan was to renovate a former department store building, which was purchased by the Postal Service in 1971 for $1.1 million. By 1974, those plans were abandoned as officials determined remodeling costs would be much higher than anticipated.

The contract to construct a new, $2.8 million post office building in Waterloo’s downtown district was officially approved in June 1977. The 105,000-square-foot modern facility opened its doors less than two years later; the Waterloo Post Office remains in the same location today.