I have no clue what he's talking about here.
There was never a formal promise of land made to the slaves.
Freedmen who acquired land often were pressured to sell it back to white men, or killed it they refused. But those white men were very seldom, if ever, immigrants.
Something about General Sherman and 40 acres & a mule or some such. Fine, we have LOTS of land in Alaska, Idaho and etc. and I’m sure the mule ranchers will be happier than hell to sell us several million.