To determine the date of when the fireplace was moved, it was necessary to first date the existing chimney stack. To date the existing chimney the Restoration Team looked at documentary evidence, including a letter that President Madison's carpenter James Dinsmore wrote Madison that describes taking down the chimney, and physical evidence, such as the types of bricks used to build the chimney. As a result it was concluded that the existing chimney was built in ca. 1812 and so the ca. 1764 chimney had to have been removed at the same time.