When the institution of slavery was legal and enslaved people considered property slaveholders had to file and pay property taxes. These records were compiled in an online database by Ancestry Library. The Pennsylvania Tax & Exoneration records serve as further proof that 18th Century Trustees of the University of Pennsylvania owned enslaved people.
William Allen's biography on the University Archives website says that he freed the enslaved people who he held in his will. In his will, which is available at the Historical Society of Pennsylvania, he states 'I do hereby manumit and make free all of my Negro Slaves' confirming the claim in his biography. Thus we know, that Allen held enslaved people up until his death in 1780. As this is the only version of his will available, we also know that he did, indeed manumit the people that he held in bondage after his death.
William Bingham was taxed for two enslaved people in 1769 and one enslaved person in 1782 and 1783.
According to the Pennsylvania Tax & Exoneration Records, 1768-1801 on Ancestry.com Dr. Thomas Cadwalader held two enslaved people in 1769.
William Masters was a Founders and early trustee of the University. According to one source, Masters owned an “astonishing number of slaves” on his plantation. According to an inventory from 1740, there were at least 34 slaves on the property. When Masters died in 1761, his remaining slaves were inventoried and sold a few weeks later.
Robert Morris, a merchant who Founded the Bank of North America, owned slaves up until 1797. Both in his involvement in trade and his own ownership of enslaved people, his wealth was tied to slavery, which certainly improved his ability to found the Bank.
Caspar Wistar was a renowned Professor of Anatomy at Penn and trustee. He was President of the American Philosophical Society, the Pennsylvania Prison Society, the Humane Society and the Society for Circulating the Benefit of Vaccination. Gen.Potter, as one of the largest landowners in Pennsylvania, utilized slaves to work that land.