Designed by architect J. H. Suttle, the 1911 McKinney Post Office is a characteristic and well-preserved example of an Italianate post office. The tile roof, ornamental columns, eaves and window configuration are common to the American post office after 1910. These elements and the three-bay arched recessed entry define the facade. The fourth post office to serve the area, the structure was deeded to Collin County by the federal government in 1959 and in 1982 became a Collin County museum. Recorded Texas Historic Landmark - 1997