Prentiss L. Harrison was one of the first-ever physician assistants (PA), as well as the first African-American physician assistant.
The PA Profession
PAs are still a relatively new profession--and definitely a trendy one. PAs are health care providers who see patients, prescribe medication, order and interpret tests, and create treatment plans. They generally work in conjunction with a physician, though in some states, they can practice independently.
The conditions for creating the PA profession come from the 1940s-1960s: The successful fast-tracking of physician training during the war, the proved knowledge and capability of military-trained medical corpsmen, an increase in medical specialization (creating a need for primary care providers), an increase in medically-insured Americans, the creation of Medicare and Medicaid, and a perpetual need for health care in poor and rural populations. , 
Taking these factors into account, Dr. Eugene A. Stead spearheaded the creation of the first-ever physician assistant program at Duke University in 1965. The first class consisted of four former US Navy Hospital Corpsmen.  One source writes, "The physician assistant, who was initially viewed as a physician substitute, was trained to provide medical care to rural and other medically underserved populations with physician supervision." 
As of March 2020, there are now some 250 PA programs in the United States.  PAs practice in all 50 states, as well as internationally.
Prentiss L. Harrison
Prentiss L. Harrison was a member of Duke University's second class of PAs, which means he was one of the first PAs ever. He is also the first black physician assistant. Here's more info about this awesome person:
Harrison was born in Texas, where he graduated from high school in 1961. He enlisted in the US Army where he was trained as a medical corpsman. As such, he was exactly what the new PA profession was looking for. After his time in the Army, he was accepted to PA school and graduated from Duke University's second PA class in 1968.
Harrison worked in various capacities as a PA, but these are some of his career highlights:
Harrison was the first PA to work in New Jersey--before the state had even passed legislation to enable PAs to work! After five years at the Princeton University student clinic, a nurse reported him to the state medical board, who barred him from practicing in New Jersey. His supervising physician and the University were prepared to fight for him, but he elected to move to another state to practice.
He worked at the Ben Taub General Hospital, affiliated with the Baylor College of Medicine--and was the first PA to receive privileges there. He was also a junior faculty member for Baylor during the time they were establishing their own PA program.
He was a provider in a number of underserved areas, including staffing one of the first rural satellite clinics in the country (in conjunction with Duke and Lincoln Hospitals); working for the Indian Health Service on a Sioux reservation in North Dakota; providing care in Mountain Village, Alaska; and working for Baylor's Thomas Street Clinic.
From working at Baylor's Thomas Street Clinic, Harrison developed a special interest in working with patients with AIDS, with a particular focus on pain management.
Harrison established two clinics, the I-10 Family Clinic in Huston, Texas, and the Trinity Valley Medical Clinic in Liberty, Texas--again, a pioneer, as there are still not many PAs who establish their own clinics.
In addition to working as one of the original PAs, Harrison was an advocate for the profession. He worked to educate physicians and others about PAs, and was a preceptor for many PA students.
Harrison also focused on advocating for African-American PAs. He was a founding member of the African Heritage PA Caucus, formerly the Minority Affairs Committee, of the American Academy of PAs (AAPA), in the early 1970s. The PA Foundation now has a scholarship named in his honor.