de bene esse: literally, of well-being, morally acceptable but subject to future validation or exception
U.S. Grant is more relevant today given the publicity about a segment of the Texas population seeking to secede.
Here is what Grant had to say about the Texas territory in his memoirs: "Texas was originally a state belonging to the republic of Mexico... it had but a very sparse population, until settled by Americans who had received authority from Mexico to colonize. These colonists ... introduced slavery into the state almost from the start, though the constitution of Mexico did not, nor does it now, sanction that institution..."
Yes, Mexico outlawed slavery before the U.S.