Forcing people to work without recompense is slavery. So should not all the people that see slavery as the greatest of all evils object to welfare? Is not the whole idea of welfare is making people work for the non working part of the population in order to get their (of the non workers) votes? So former slaves do not object to slavery when they get to be the masters.
So when people criticize the USA for having had slaves, you might ask these same people if they object as strongly to welfare? i.e. giving money to people for not working. Why do they not lobby the Congress to abolish all welfare payments? [Maybe they like the money?]
[I thought to add that the General Welfare clause of the Constitution (i.e. for what the Congress can make taxes for) means the general welfare of all the people of the USA--not to take from one group to give to another. This is a common place fact in Constitutional Law]
