The Dr. William Henderson House (31 E. Main St.) was listed on the National Register of Historic Places in 1978. Portions of the content on this web page were adapted from a copy of the original nomination document. 
The Dr. William Henderson House is a three story, Federal style, town house. Excellently preserved, the house is brick laid in common bond with a stone foundation. It has a gable roof with gable end brick chimneys. The house has a three story rear extension with a shed roof and two story porch on the east side. A one story frame addition was added to the rear circa 1918 and was later raised to two stories. The heavy front cornice is decorated with heavy dentils.
The original brick house is three bays by four bays. Window sills, lintels and stoop are made of Hummelstown brownstone. Windows are six over six, many with original glass. Third story windows are eyebrow windows of three lights. Small fanlight windows are located in the gable ends.
The front door is located in the first bay. This deeply set doorway has panelled jambs and a heavy classical entablature decorated with small dentils. The stone lintel covered by the entablature has the carved names of the builders: Dierdorf and Pamler, and the date of construction: 1829.
The interior of the house is in a excellently preserved state with original flooring, plaster, fireplaces and some hardware. The side stairs have fine oak banisters and round handrail which extends to the third floor. Double fireplaces are located in the west wall on the first and second stories. The eastern chimney is blind, merely decorative. Between these small fireplaces are located built in the wall cupboards. Heavy sliding doors separate the livingroom from the dining room. The kitchen is located on the first floor of the rear section. A heavy firewall is located between the sections. A large walk-in fireplace is located in the rear wall of this section. Double stairways are located to the left of the fireplace. One stairway leads to the full stone lined cellar with dirt floor. The other leads to the second floor bedroom.
All rooms are original in size and shape and have been little altered. The second floor front clothes room has been converted to a modern bathroom. At the rear of the lot is a modern garage built over the site of the original carriage house.
Lot Number 10 on the plan for Hummelstown, now 31 East Main Street, belonged in 1820 to Dr. Duncan King, and in that year his widow Catherine Luther King, and her brother Cornelius Luther and children of Dr. John Luther, applied to the Orphan's Court to sell the property to satisfy Dr. King's debts. At a public sale on January 24, 1820 the property with a two story log house was sold for $870.00 to Dr. William Henderson. Born in Cumberland County in 1795, William Henderson read medicine with Dr. Sampson of Shippensburg and graduated from the University of Pennsylvania in 1818. He set up practice in Hummelstown in the same year and continued practice until his death in 1849. His wife was Mary Wolfersberger of Cambellstown, Lebanon County.
He built his fine three story brick house in 1829. Because of its size and grandeur his home was often referred to as a mansion.
Upon Henderson's death the property was sold to a Henry Miller. In 1877, it was purchased by George R. Fox, the grandfather of the present owner. The Henderson house is a finely preserved Federal style house both on its exterior and interior.
Dauphin County Records of Deeds.
Egle, A. H. Commemorative Biographical Encyclopedia of Dauphin County, Pennsylvania. Chambersburg, Pa.: J. M. Runk & Company, 1896.