Most of the slaves who “migrated” did not come to the United States at all. Went farther south.
It’s been estimated that 6% were brought to the US, 94% went further south. About a third went to Brazil.
As far as I know, there is no effort to shame Brazil. America is affluent; America is shamed/blamed. It’s all about money. Haiti had lots of slaves, but there is no point in shaming Haiti as they are dirt poor.