Woodlawn Plantation was once home to George Washington's nephew Lawrence Lewis and Lewis' wife "Nelly." The Federal main residence was completed in 1805 according to the design of William Thornton, architect of the national Capitol. During the Lewis' residence at least 90 slaves lived on site. In 1846, the property passed on to two Quaker families, the Troths and Gillinghams, who wished to prove that abolition of slavery would not destroy the Southern economy. To this end, they hired Caucasian and free African American farmers to work their land, rather than relying on slave labor. Their actions were unique and highly controversial during their day.

The plantation offers period rooms, guided tours of the residence, group tours, and private teas. Groups of 10 or more are required to call at least one day in advance for reservations and confirmation of availability. The second floor is not wheelchair accessible. Tea programs are available to groups of 12 or more in April through December.

This 18th-century building was restored to house the Hugh Mercer Apothecary. Dr. Mercer served the citizens of Fredericksburg with medicines and treatments of the time. Leeches, lancets, snakeroot, and crab claws made up just some of the remedies. Dr. Mercer practiced medicine for 15 years in Fredericksburg. His patients included Mary Washington. Dr. Mercer left his practice to join the Revolutionary army and died as a Brigadier General at the Battle of Princeton.

The site offers tours.

The Miller Place - Mount Sinai Historical Society has two historical properties that can be toured in the summer or by appointment at other times of the year. The Miller House was built in 1720 on land bought by Andrew Miller Sr., an English immigrant who worked as a cooper, in 1670. The other property, the 1820 Daniel Hawkins House was home of the Hawkins family from Setauket and is located just east of the Miller house.

Tours are available upon appointment. There is no specific educational programming for school groups so the teacher will have to work with the museum to design a field trip.

The Ball-Sellers House is an example of an ordinary 1700s home, built and inhabited by mid-18th-century yeoman farmer and miller, John Ball. The original logs with daubing, wide plank floors, and rare clapboard roof remain to this day.

The house offers an interpretive docent.

Built by Charles Washington around 1760 as his home, this frame building became a tavern in 1792, operating in the bustling town of Fredericksburg. The Tap Room features a reconstructed bar cage and fine collection of 18th- and 19th-century English and American pewter. Another spacious room provided a space for meetings and private dinners by patrons of the tavern. "Tavern wenches" provide visitors with a lively interpretation of 18th-century tavern life. The tavern is filled with period furnishings and stories of early life in Fredericksburg.

The tavern offers tours.

The St. James's House was built around 1768 and is one of the few 18th-century frame houses still standing in Fredericksburg. The house is particularly noted for the collection of antique furniture and decorative arts assembled by Daniel Breslin and William Tolerton, who restored St. James's in the mid-1960s. St. James's represents Messrs Breslin's and Tolerton's interpretation of an 18th-century townhouse in that the furnishings are probably more formal than what would have been in the house during the time of its original owner.

The house is open for tours by appointment.