Slate Hill Cemetery, also known as the Old Stone Cemetery, Slate Pit Hill Graveyard, and Yardley Cemetery, was deeded to the trustees of the Falls Monthly meeting in 1686 by Thomas Janney. His son Abel Janney donated the second plot of land in 1720, and Colonel Joshua Anderson and Elizabeth Anderson gave a third section in 1799 for use as a public cemetery.

Slate Hill has the oldest known headstone in Bucks County, dating to 1698. Since the cemetery started as a Quaker cemetery, the earliest burials did not have headstones. Unfortunately, the earliest records for the Quaker side are a map completed in 1926 and currently found at the Mercer Museum. As of 2025 the Historical Commission is working on a comprehensive map to identify as many of our missing residents as possible. Ground penetrating radar was utilized to develop a map and identify where stones are missing and researchers are utilizing the 1926 map and other inventories to match the location of the burials with a person.

The side donated by Colonel Anderson became a segregated side. In 1990, the township of Lower Makefield (LMT) took responsibility for both sides after the Falls Meeting gave them the deeds. The earliest map of the segregated side is from the early 90's after LMT took possession

After LMT took possession the Historical Commission worked hard on the site, making a comprehensive inventory of the headstones and getting some of them professionally fixed. Work was also done on the stone fence surrounding the property. They also got the site added to the National Register of Historic Places in April 1992.

The current Historical Commission has begun interpretative activities including reinstating Ghost Tours, adding QR codes, and promoting the site on social media. They have gotten all the stones cleaned; volunteers cleaned up landscaping, and a Keystone Preservation grant was received from the PA State Historic Preservation Office to restore some of the broken or fallen headstones in 2025. In 2024, the township was awarded a Community Initiative Award for exemplary work in preserving a historic resource and engaging the community in in its importance by PA-SHPO.