In 1789, President Washington designated Wiscasset an official U.S. Port of Entry and appointed Francis Cook Inspector of Customs. Every ship entering the country had to present documents identifying the vessel, cargo, and country of origin, and customs fees were the government's primary source of revenue before taxes. Cook served for 38 years. Wiscasset's first Custom House was a small structure next to Cook's house on Main Street, and the second, another brick building on the waterfront, was destroyed in the devastating fire of 1866 that burned most of the waterfront. The present Custom House was built in 1870, with the Custom Office on the second floor and the post office on the first. In 1913, Wiscasset's designation was discontinued and the Custom Office closed, but the U.S. Post Office remained there until 1961. Afterward, the building became a residence and retail space. It was also seen in use as a gathering place when a huge crowd came to see Arctic explorer Captain Donald MacMillan depart on the Bowdoin for his 1925 Arctic Expedition.