The University Archives profile on Kinnersley includes his wife’s labor running the dormitories, maintaining dorm hygiene, and doing laundry. Outside of his life at Penn, Kinnersley was a leading scientist of the day studying electricity, and he was ‘the principal collaborator’ on Benjamin Franklin’s projects in the 1740s and 1750s.
Kinnersley traveled throughout the colonies showcasing his and Franklin’s inventions. On one trip in 1749 to Maryland and Virginia, Kinnersley demonstrated the power of electricity to audiences. In one of his exhibitions, he revealed an electric current's path through water by having it ignite some liquor located 200 yards away. Later in the trip, Kinnersley demonstrated a form of primitive shock therapy on participants, claiming that electricity applied to the human body can cure “tooth ache, pains in the head, deafness, pains in the limbs, which had been so violent as to take away the use of them, pain in the stomach, swelling of the spleen, sprains, relaxation of the nerves.” Of particular note in these experiments was his cure of Samuel Miller, who was unable to raise his arms above his head, and of a “negro boy’s” deafness. Presumably, Samuel Miller was white because his full name was listed in Kinnersley's notes; this is one of the ways we know that Kinnersley experimented on both white and black bodies.
Tax records from 1767 and 1769 indicate that Kinnersley owned one enslaved person. Additional documents suggest that Kinnersley enslaved a man named Caesar. This would have been during the time that Kinnersley was Steward of the dormitory. The College paid Kinnersley for “his negros Services at the Academy in Ringing the Bell making Fires.”
The Daybook notes continuous payments for Kinnersley’s enslaved man’s work – whose labor began October 25, 1756 – with payments beginning in January 1757. The last payment that directly mentions his enslaved man’s work is from January 1770. While the payments directly mentioning Kinnersley’s “negro” stop in 1770, Kinnersley continued to receive a second salary until his retirement in 1770, suggesting that he was still being paid for the enslaved man’s work on campus until 1770. The term “2nd Salary” is used in the College’s Account Book in 1768 and 1769 as well, when the 2nd salary referred to was the enslaved man’s work. Researcher Dillon Kersh believes it is likely that the enslaved man worked on Penn’s campus until Kinnersley’s retirement in 1770. In 1872, over 100 years after Kinnersley's retirement, Penn installed a stained-glass memorial to Kinnersley on the first landing of the east staircase of College Hall, the main building on campus. The memorial was taken down sometime after 1918, which it is last referred to in the records, although when it was taken down is a question that requires further research.
After Kinnersley retired from Penn in October 1772 for health reasons, he traveled to Barbados on the Brig Rachel in early December 1772 to spend the winter in a warmer climate. In a March 13, 1773 letter to his wife in Philadelphia, Kinnersley wrote:
‘Caesar was taken very ill last week with a pain in his bowels, which at last settled in his side, bleeding and some doses of physick have made him pretty well again.’
The nature of the letter was to inform his wife of his own health conditions after a winter in the Caribbean, and it is very personal in tone. Thus, including information about Caesar before an update on his own health implies that this is someone who would be intimately known to his wife, and is someone relevant enough to warrant a mention in the letter. The letter mentions Kinnersley’s desire to return to Philadelphia soon, and presumably, since Caesar appears to have recovered from his illness, he makes the return voyage with Kinnersley.
In 1774, Kinnersley was again taxed for one negro. Based on the fact that Kinnersley was paid for his enslaved man’s labor from 1757-1770, the documentation of Caeser's presence during the voyage to Barbados not long after Kinnersley's retirement, and a tax record recording only one enslaved man in Kinnersley's possession from1767-1774, it is reasonable to conclude that Caesar is likely the name of the enslaved man who worked on Penn’s campus. More research needs to be conducted into the life of Caesar to confirm without a doubt that he is the same man who worked on Penn’s early campus and to try to recover something of his own life experience.