The park made some changes at Washington's Headquarters. They did away with the 10-cent admission fee but allowed the caretaker they installed there to sell souvenirs and collect a 10 percent commission. [43] A stone wall soon replaced the old picket fence that had long surrounded the building. In the decade after they got their hands on the Centennial and Memorial Association's money, they repainted and refurbished the house and began a refurnishing project. The park commission concluded that none of the original furnishings from the encampment period could be traced and decided to furnish the building in the general style of the late eighteenth century. [44] Furniture was purchased from John Wanamaker, owner of a large Philadelphia department store, and Alfred Lewis Ward. The project was supervised by Ward's and Wanamaker's decorators. [45] A park commissioner demanded that the furniture supplied by the Chester County DAR be removed, and in 1914 the organization complied. [46] Furnishings supplied by other DAR chapters remained in place at that time. When the refurnishing project was done, the building was protected from the winter's cold and damp by a new heating system that brought warm air through pipes from another source, greatly lessening the danger of fire in the historic building. [47] In 1917, a magazine article commented: "The details of the restoration are throughout so complete that in every room the past seems very real." [48]

During Governor Pennypacker's administration, the park was also able to acquire new land. In 1904, the park commission purchased land along what would have been the camp's outer line defenses, where many brigades had camped. In 1906, the park acquired several contiguous parcels where other soldiers had camped, and a few other tracts to straighten out the boundaries. [49]

This expansion brought a second structure within the park's boundaries in 1906: a parcel with a dilapidated old building that had rotting rafters and floors. At the time, the building was thought to have been a schoolhouse built between about 1790 and 1830. [50] One aging area resident remembered attending school there around 1824 or 1825. [51] The structure had more recently been used as a stable and henhouse. [52] Another former area resident said that her elderly sister remembered it as "a very old building occupied by Negroes, when she was a little girl."[53] When Governor Pennypacker arrived to inspect the schoolhouse, a local newspaper reported, "a casual examination by the Governor of the state at once convinced him that the structure was of a much earlier date. He soon found the date 1783 cut by a schoolboy, with his initials." [54]

Having decided that this additional structure was historic enough to remain standing, the park commission began restoring it—and found what they considered to be evidence of an even earlier date. Old stones dug out of the foundation showed carved names of two more schoolboys and the years "1714" and "1716." [55] The park commission report printed at the end of 1908 stated: "From records obtained by a member of the Commission it is ascertained that [the schoolhouse] was built in 1705 by Letitia Penn Aubrey, a daughter of William Penn." [56] Because the park commission did not identify these records, and they have never been rediscovered, and because the carved "1714" and "1716" were never discovered in later work on the building, the quality of this evidence cannot be judged.

The park commission concluded that the school must have functioned as a hospital during the winter encampment, but they restored it as a school. Restored field hospitals were popular in military parks, but in roughly the same time period a log hut was being built and fitted out as a hospital at Valley Forge. [57] The "Letitia Penn Schoolhouse" ended up with a master's desk, student benches, a blackboard, and inkwells. One visitor commented that it had been "restored with a faithfulness to detail which even includes the dunce's cap." [58] The park commission discussed allowing the widow of the park's first caretaker at the Headquarters to set up a little business there selling souvenirs. [59]

Current research indicates that the park's enthusiasm for this building was a bit misplaced. It is now once again believed to date from between 1790 and 1810, or perhaps later. [60] It certainly did not owe its existence to Letitia Penn Aubrey. Although it was situated on land that William Penn had reserved as a manor for his daughter, a grant that was confirmed to her in 1701, it is doubtful that she and her husband did anything with this land besides attempt to sell it for cash.