By MICHAEL CASSS, The Tennessean

NASHVILLE, Tenn. (AP) _ They were relatively young people of African descent, worn down by years of hard labor.

Six of them had arthritis. One man walked with a limp, and a woman endured fractured vertebrae in her lower spine. A young, probably heavyset man had a damaged hip _ and maybe sickle cell anemia, too.

They were almost certainly slaves on the old Grassmere farm, a large tract of land in South Nashville that’s now used for a different purpose: the home of the Nashville Zoo.

Remains that were dug up at the zoo to make way for a bigger, $6.8 million “entry village” appear to have belonged to African-Americans buried in a slave cemetery at Grassmere, DNA and skeletal evidence has revealed.

Shannon Hodge, an archaeologist at Middle Tennessee State University, and her students looked at the remains of nine people in May. Evidence showed all nine were under the age of 50 when they died, and seven “had traits of the skull that suggest African ancestry,” Hodge wrote in a blog post for the Tennessee Council for Professional Archaeology’s website.

Archaeologist Larry McKee of TRC Companies Inc., which excavated the graves last winter and found full, well-preserved skeletons and numerous buttons, beads and other artifacts, had already determined that the people in them were buried between the 1820s and 1850 before Hodge went to work. That finding, combined with the skeletal and DNA evidence, shows that the once-forgotten cemetery near the zoo’s ticket booths “almost certainly represents a community of enslaved African-Americans in the last decades of American slavery,” Hodge wrote.

Before the digging started in late February, McKee said his instincts told him the people in the graves were tenant farmers buried sometime after the Civil War, though he wasn’t sure exactly why.

The science told a different story.

“It really changed my thinking on the history,” McKee said Thursday. “I’m thoroughly certain that what we’ve got now is part of the enslaved community using that as a burial ground.”

Tori Mason, the zoo’s historic site manager, said the discovery “gives us another piece of our puzzle” to help explain the history of Grassmere.

In June, McKee’s team reburied all of the recovered remains not far from the family cemetery near Croft House, the approximately 200-year-old home west of the zoo’s carousel. Mason said the zoo hopes to host a dedication ceremony this fall.

The archaeologists dug up 19 graves, finding remains in most of them. The adults tended to be tall for the time _ 5 feet 8 inches to 6 feet 1 inch _ and had very good teeth. They appeared to have been well-fed, and they were buried in clothes, whereas some slaves at other sites were simply wrapped in a shroud, Mason said.

But their circumstances, of course, were far from ideal. Hodge wrote that six of the nine adults whose remains she studied “had arthritis of the knee and/or spine, suggesting demanding workloads.”

One of them, possibly ground down by the life of a slave, never even got a chance to grow up properly.

“The youngest of the adults was an exceptionally tall and robust young man in his late teens or early twenties,” Hodge wrote. “He had a slipped capital femoral epiphysis _ meaning that the `ball’ part of the ball-and-socket joint that makes up the hip was damaged before he finished growing. In modern times, this condition is most commonly found in African-American teenagers, particularly boys, and especially ones who are tall and heavy. In this case, it might have also resulted from heavy workloads and stress on the hip joint at too young an age.”

But the “respectful” way the slaves were buried suggests that the owners “thought enough of the people working for them that they allowed their loved ones to honor them that way,” Mason said.

Although zoo officials and the archaeologists still don’t know any of the slaves’ names, they’ve started working on exhibits “to tell exactly who these people were, to what extent that we know,” Mason said.

“It gives us another part that we’re going to be able to interpret now that we’ve never been able to do before,” she said. “We do know that the family had slaves.”