The earliest known person with HIV-1 was a man in Kinshasa, Democratic Republic of Congo, in 1959, according to The Aids Institute. The man's name is not listed, and how he became infected is unknown. Scientists speculate that chimpanzees hunted for meat transferred the virus to humans through infected blood.
The HIV virus began as the simian immunodeficiency virus, or SIV, in chimpanzees from West Africa, notes The Aids Institute. It is believed that the HIV-1 virus stemmed from a single virus as early as the 1940s or 1950s. From the first known human infection in 1959, the HIV virus spread across the globe fairly quickly. Evidence suggests that HIV was present in the United States as early as the 1970s.