History of Slavery in the U.S. for a gifted 11 year old

My son has been asking a lot of very deep questions about the history of slavery in the U.S. Once he’s fixated on a topic there is no ending to the questions, but I can’t give him enough detailed information.
What was daily life like?
Why would people own slaves?
Were there people who opposed? Etc
(I’m pretty good at giving him answers to all the above but it’s clear he wants even more details)

I’m looking for some books that might balance the fine line of someone who needs more than a glossed-over version for kids, but perhaps a bit less of the more graphic realities …

by SwampWight