Bannerman told me that on his father's side, some of Biden's ancestors enslaved people.

He pointed to Biden's great-great-great-grandfather, Jesse Robinett, who enslaved two people in Allegany County, Maryland, in the 1800 census. Another 3rd-great-grandfather, Thomas Randle, enslaved a 14-year-old male in the 1st District of Baltimore County, Maryland, in 1850, he said, citing census records and slave schedules, which were separate headcounts of slaves conducted alongside the census in 1850 and 1860.

https://www.politico.com/news/magazine/2021/09/14/how-joe-biden-became-irish-511637?nname=playbook&nid=0000014f-1646-d88f-a1cf-5f46b7bd0000&nrid=0000015d-df62-d5b7-af5f-fff3c0e70000&nlid=630318