Ashburton House, also known as St. John's Church Parish House or British Legation, is a house on Lafayette Square in Washington, D.C.. The house stands at 1525 H Street, N.W.
It was the site of 10 months of U.S.-British negotiations leading to the Webster-Ashburton Treaty of 1842. This settled U.S.-Canada border disputes and ended the Aroostook War.
It was declared a National Historic Landmark in 1973.
Mathew St. Clair Clark, a House of Representatives clerk, began the original brick building in 1836. Shortly afterwards, it was sold to the British government. Lord Alexander Ashburton took up residence in the house in 1842, the same year he and Daniel Webster negotiated the Webster-Ashburton Treaty in its parlor. Ashburton was succeeded by novelist Edward Bulwer-Lytton; both made changes to Clark's design. The house received its French Second Empire design in the 1870s. The architects for both the 1853 and c.1870 remodelings are unknown. In the early 1950s, the house became the parish house for nearby St. John's Church.
The house is in excellent condition and continues to serve as the parish house for St. John's Church.