Mail equipment was transferred to the new post office in the Clinton County community of DeWitt on Friday, July 14, 2000, and the new facility was officially opened to customers the following Monday. The new post office offered dedicated customer parking, a 24-hour lobby, and about twice the square footage of the previous location.

The previous post office was constructed in 1936, one of several built across the state as part of the Works Project Administration. After sitting vacant for nearly a year, the City of DeWitt purchased the building and renovated the interior for use as the City Hall.