Well, it's not the Ku Klux Klan, as that was a large group of people who wanted to have slaves all return to their work, I've never heard of C, and we barely touched on D in school. From what I've learned, however, the Freedmen's Bureau helped former slaves by supplying food, providing education and homes, etc.
Economic hardship and distrust of Virginia colonists who were unable to acquire land
In short, some countries were not benefited in the trade sector
One similarity is that at one point they were allies.