The Flemish-bond brick building known as Marshall Hall stands overlooking the Potomac River to the north. The oldest portion of Marshall Hall was built c. 1725, and was five bays wide by two bays deep, and two stories high with large flush chimneys. Flanking the central entrance, which had a transom and had been narrowed at some point, were two large 2/2 sash windows to each side. These windows and the door had splayed brick arches of rubbed and gauged brick, the bases of which were molded in a double-ogee pattern creating a highly decorative effect. The five 2/2 sash second-floor windows were shorter, with flat unornamented heads flush with the base of the roof cornice. Two bays were added to the east gable end of the house in about 1760. Also of Flemish bond brick, this portion of the building held a door in the west bay of the north facade. A slightly smaller flush chimney rose from the east gable end, but the chimney stack between the two brick sections was retained. The south, or rear, elevation of the house was five bays long, with the three bays on the west end marking the original house. The two first-floor windows and center door of this part of the house had segmental arches of alternating stretcher and header brick. Those on the second floor were unornamented and flush with the base of the roof cornice. The first-floor window and door on the addition are closely spaced together and occupy a former doorway, the arch of which is still discernible. Both first-floor openings have flat arches while those on the second floor, like those of the older part, are unornamented and flush with the roof cornice. All windows on this elevation also held 2/2 Victorian sash. A photograph taken c. 1900 shows a Victorian porch with elaborate brackets spanning this entire elevation. Before renovation in 1966, the west gable end displayed a large flush chimney decorated on its outside face by an arched blind panel extending up from about the middle of the gable to just below the corbeled chimney cap. In 1966 the chimney stack was rebuilt above the gable peak, and though the panel was rebuilt, the arch was not. A closet window in this gable end was bricked up at an unknown date, as were two window openings on the east end of the house. Two windows pierce the second floor of the west gable end. The roof of the building flared at the eaves. Photographs from the 1950s and 60s show a modillioned cornice with ogee crown and bed moldings decorating the front and rear elevations, but this was removed in 1966. The basic interior plan was retained, along with a substantial amount of interior fabric. In 1976, the National Park Service bought the property, and planned to restore the building. On October 17, 1981 the house was completely gutted by an arson fire, leaving only the brick walls standing. The 60' x 30' walls were stabilized and fenced off until the building suffered yet another accident on January 12, 2003, when a large truck drove straight through the center of the building and out the other side. The bays destroyed on the south facade were the entrance bay and the bay to its east, and on the north facade, the entrance bay and the two to its east. Effectively, the central third of the building was completely destroyed.
Marshall Hall was the largest dwelling house in Southern Maryland to be documented as dating before 1740. Despite extensive alterations, it retained in 1980 a surprising number of original features, many of which were the earliest datable examples yet recorded in Maryland. Such early features included the double-ogee window heads of the river front, the bolection molding framing the fireplace of the great room, the four-room plan which became a standard favorite in the region and continued in popularity until about the second decade of the 19th century, the unusual framing of the roof, and the arched blind panels decorating the chimney stacks. The east end addition itself is of interest for the original south doorway opening onto a recessed porch. It is for these reasons that Marshall Hall was invaluable for use in comparative studies tracing the architectural development of the region. Although these features are now largely lost, of equal importance is the association of the house with one of Southern Maryland's most socially prominent and affluent families. Contemporary records indicate that Marshall Hall was the largest brick house standing in Charles County between 1710 and 1740. The family itself was the third wealthiest in the county in the 1730s. Both private and public records relating to the house and the Marshall family are remarkably complete and provide a highly interesting insight into the life and times of a prosperous landowning family of 18th century Southern Maryland.