In his article "P.T. Barnum, Joice Heth and Antebellum Spectacles of Race" (American Quarterly 51:1, 1999), Benjamin Reiss writes that:
"Heth's autopsy appears as a moment in which science--mediated by popular journalism and other mass media--faced some of the crisis of legibility, authenticity, and recognition brought on by the process of modernization."
So was Heth really that old? Of course, many suspected that Barnum and Heth were not telling the truth, and so to solve the issue they needed a purely objective means of inquiry. Enter science. At Heth's death, Barnum made a small fortune by selling tickets at 50 cents apiece to 1,500 people who would witness Heth's dissection on a make-shift operating table set up in New York's City Saloon. Dr. David Rogers performed the autopsy and concluded that Heth was a fraud, not more than 80-years-old. But then Barnum two days later said Heth was still alive, and the autopsy was performed on a Harlem woman called Aunt Nelly.
There's no doubt that Barnum was playing a confidence game. But so was science. Racial anatomists at the time, such as Dr. Caldwell, claimed he could more easily distinguish between black and white human skeletons than a dog from a hyena or a horse from an ox. Science was being used to propagate some pretty evil agendas at the time. Legal decisions like Dred Scott and the Fugitive Slave Act were decades away, and they were heavily impacted by racial "science."
Joice Heth, I'm sorry people treated you and your corspe so disrespectfully.