Why did many former soldiers who came home from WWI resent African Americans?

There is one main reason.

Explanation:

It's actually quite simple, it was the norm. People wanted to fit in and the norm of this was to be bitter against African Americans. They used tactics like lynching (hanging them) or just using whatever racial slurs possible.

bibliography and citations to credit the sources hope this you if not my deepest of apologize ^w^

payments were made after the 1940s.

in the 1980s, a commission held investigations and made recommendations.