“The Constitution doesn’t use the word slave . . .”
That is an interesting comment and brings to mind a retired union firefighter who fled from up north and moved into town not far from our place several years ago.
He liked to do two things: tell everyone how they used to do it up north and multiply by zero. He was the Einstein of multiplying by zero.
Multiplying by zero never accomplished anything for him; never changed any facts. But he could do it, enjoyed doing it, and was quite good at it.
The Constitution doesn't use the word slave
Correct. It uses the word slavery.
13th Amendment, "Neither slavery...."
What was this slavery thing referenced in the 13th Amendment?
By that time, the former slaves of the so-called Confederate states had been freed by the United States Army.
Only a few recalcitrant Union states then still had lawful slavery.
“. . . and neither is there a constitutional right to secession.”
I also note the constitution does not give the states the right to permit the sale of unbolted table grits.
That is because the constitution was not a grant of delegated power by the federal government to the states. The constitution was compact by the states to give limited, delegated powers to the federal government.