Next to the Arlington Building on H Street is the old-fashioned dwelling known as the Ashburton house, from its connection with the historic Webster-Ashburton Treaty – which adjusted the Canadian boundary line in 1845, settled a fisheries dispute on the north Atlantic coast and provided a means of cooperating with Great Britain in dealing with the slave traffic.
This house was the British Legation at the time. Lord Ashburton, the British Ambassador, and Daniel Webster, then Secretary of State, who live farther along the square, dined and wined each other and spent long hours and delicate negotiations of their countries' difficulties at Ashburton house or at the Webster home. The house was built by Matthew St. Clair Clarke, Clerk of the House, during 1822-34. In 1849 and again became the British Legation, this time under Sir Henry Bulwer, brother of the English novelist known as Bulwer-Lytton. - Washington City and Capital, 1937, Lafayette Square section, pg. 655
Since the early 1950s, the Ashburton house has been the parish house for the nearby St. John's Church. The house is in very good condition. Was listed as a National Historic Landmark in 1973.