Samuel Hensdale Johnson was born January 8, 1900 in Key West, Florida, the oldest of seven children born to Mr. and Mrs. Samuel D. Johnson. His parents were originally from the Bahamas and the family moved to Miami in 1903.

Johnson was an outstanding student throughout his life and as a result of his academic record in Meharry Medical School, Johnson was offered a fellowship at the Mayo Clinic at the University of Minnesota. Johnson did not accept this offer as it included a stipulation which required a year of study at the Mayo Clinic. Johnson felt that he had an overriding responsibility to assist his sisters and brothers, four of whom were enrolled in college at that time. Instead, he accepted an internship at City Hospital in Missouri, which allowed him to return home after one year and established a general practice in the Miami area. He was then able to work to support his younger siblings, who were in college.

In 1937, after completing his residency in radiology in Chicago, Johnson returned to Miami and became the first African-American physician in Southeast Florida to establish a private practice in radiology. In addition to his private practice, Johnson also served as the staff radiology for Christian Hospital and the Family Health Center.

Johnson retired from the practice of medicine in 1974. He was a humanitarian as well as a successful physician. Johnson helped make his mother’s dream a reality by ensuring that each of her seven children completed college.