You have provided some excellent examples here of how some exploit racism through dishonest analogies, incorrect inferences, and downright dishonest captions.
Take the captions for the illustrations you linked for instance:
Holocaust - never forget.
Pearl Harbor - never forget.
The Titanic - never forget.
Racism/slavery - just get over it.
This is absolutely how the Left keeps the fires of racism hot and inescapable.
No Conservative says to anybody, white or black, just get over it re racism and slavery. It was the most single mind, fundamentally religious, and do-gooder conservatives who demanded an end to racism after all.
But re the Holocaust - never forget does not mean to hate Germans the rest of your life and demand that continue to genuflect and be sorry and pay restitution forever. It means to understand how such a thing can happen and determine that it never be allowed to happen again. Certainly Jewish people have prospered and, of all people of the world, have contributed more to advancement of good things for humankind than any other specific culture can claim. Certainly modern Germans are not responsible for what their grandparents did to the Jews.
Re the Titanic - never forget does not mean to hate ship builders and trans Atlantic shipping corporation for all eternity. It means that we need to heed the advice of engineers and not ignore a plea for help. And shipping companies are not obligated to pay restritution for a bad thing 101 years ago.
Re Pearl Harbor - never forget does not mean to hate Japanese for all generations to come. Japan became one of our strongest allies and they really do not harbor any desire to bomb us now. But it means that we need to always be conscious of those who would harm us, and no to be caught unawares. If we had taken that more to heart, perhaps there would not have been a 9/11. And the modern Japanese owe us absolutely nothing at all because of Pearl Harbor.
Re slavery - nobody in America that I know of, not even the KKK, wants to return to slavery or the pre-civil rights era. But neither is any black person in America subjected to slavery by law these days. And black men like Walter Williams acknowledge that as terrible as slavery was and as cruel as it was and as indefensible as it was, he personally benefitted. He has prospered and enjoyed a great life because he is an American descended from those somebody dragged over here on a slave ship. In other words, none of us owe him anything other than respect as a self-reliant human being and American citizen.
You can listen to those who want to keep slavery alive and well and keep black people concious of how disadvantaged and incapable they are because their ancesters were slaves. You can keep them in the slavery of government dependence. . . .or. . . .
You can treat black people as intelligent, capable, and citizens worthy of respect as human beings.
Most conservatives choose the latter. Most liberals demand modern government slavery to be the norm.