Though much changed through the years, the Thornberry House survives as one of three Civil War-era structures in the park. Built in the 1840s, it was home to John and Martha Thornberry and their five children. John Thornberry operated a wheelright shop nearby, servicing the wagon traffic that frequented Sudley Mill, and he supplemented the family's income as a carpenter and part-time undertaker. With John away serving in the Confederate Army, Martha took the children to her sister's farm on Stony Ridge during First Manassas. Although the house escaped the combat, it was overrun with wounded Union soldiers following the fighting. Driven away again the ensuing year during Second Manassas, the family returned to discover more than 150 bodies strewn about the property. Laura Thornberry, seven years old at the time of First Manassas, recalled the damage nearly 75 years later: There was not an article of anything left in it. Ten men had bled to death in mother's bedroom the night before. Carpets and all furniture were out and gone... The old farm well in the back yard was full of everything that would go in it, such as china ware, cooking utensils, flat irons, and everything you can imagine used by a family. How we all cried over it; and no prospects of replacing any of it. In the years following the war, the building served as the Sudley Post Office.