This is Washington County's third courthouse. When the county was established in 1776, the first courthouse, a combination building that served also as a market house, was built in the middle of the town square, one block east of here. It proved too small to house the government and too big and obstacle in the square. The county's affairs were moved to a new courthouse, built on the site of the present building 1818-22. That building burned in December 1871. The cornerstone of the present building was laid on October 9th, 1872. The design was by H. A. and J. P. Simms of Philadelphia and the construction was by Robert C. Thornburg. Just over a year later, on January 2nd, 1874, the County Commissioners accepted the completed courthouse and held their first meeting there. The Italianate style architecture of the building is unusual for this part of Maryland. An annex, attached in the rear was added in 1963.