The Georgian style of architecture plantation house exhibits a somewhat altered five-part plan. It was built on a Carroll family plantation beginning in 1763 by barrister Charles Carroll the Barrister, (1723–1783), a descendant of the last Gaelic Lords of Éile in Ireland and a distant relative of the much better-known Charles Carroll of Carrollton, (1737–1832), longest living signer of the Declaration of Independence and the richest man in America in his later years, also the layer of the Ffirst Stone of the new Baltimore and Ohio Railroad, just a short distance away in 1828.The City of Baltimore purchased a large portion of the former estate in 1890 as its third large landscaped park. Mount Clare has been maintained by the National Society of Colonial Dames in Maryland, the local chapter of The National Society of The Colonial Dames of America, since 1917. In 1970, it was added to the National Register of Historic Places and was designated a National Historic Landmark for its architecture.
