Ms. Ross worked in New York City in the mid-1970s and never dreamed that one of the city’s insurance companies had tried to profit from her ancestor’s enslavement. “I think it was pathetic that they used the labor, the hard work, blood, sweat and tears of the slaves” to help their business, she said.

Even so, she considers herself lucky. Her great-great grandfather survived his time as an enslaved miner. After the Civil War, Mr. York continued digging for coal and earned enough money to buy land and cattle. He helped to establish a school for newly freed slaves and became the patriarch of a sprawling family.

Others were less fortunate. The stone ruins of the Grove Shaft building, the remains of the Midlothian Coal Mining Company, are only a short drive from Ms. Ross’s home. Whenever she visits, she prays for the enslaved miners who never made it home.

Godfrey, a 50-year-old slave who was also insured by New York Life, died in a fire in Midlothian on Nov. 20, 1847.

“Burned to death,” reads the entry in the company’s accounting of the dead.

The insurance clerks on Wall Street did not record Godfrey’s last name or the location of his burial place. But they described what happened next: Mr. Mills, Godfrey’s owner, filed a claim with New York Life for the loss of his human property.

Within three months, the company delivered, paying him $337.