Claim: On the List of United States federal courthouses in the First Circuit in New Hampshire, U.S Custom House & Post Office in Portsmouth was the first one to be used as a courthouse.
Evidence: U.S. Custom House & Post Office Portsmouth 1860–1926
Now privately owned. U.S. Post Office & Court House 1935–1982
Still in use as a post office. Warren B. Rudman U.S. Courthouse 1968–present U.S. Post Office & Court House† 1889–1967
Now the state's Legislative Office Building.