Statement of Significance (as of designation - November 7, 1973):
For ten months in 1842, this was the scene of negotiations which resolved "one of the gravest and most inveterate diplomatic issues of the United States in the generation following the War of 1812": the long-standing dispute with Great Britain over major segments of the boundary with Canada. In addition, the Webster-Ashburton Treaty of 1842 saw the United States Government protect and respect the rights of the States in international affairs and stand firm against British impressment of sailors aboard American ships.