Changes: Constitutional end to slavery and granted citizenship and voting rights.
Continuities: Blacks continued to work on plantation lands doing much the same work as before 1865. They were segregated from whites and often were not given the right to vote.
I’m not sure, I would either say Spanish or French. The Spanish owned land in the North Western America, while France owned “Louisiana”
The philosophy of Karl Marx was not used to justify European Imperialism whereas European superiority allowed other races to be seen as sub-human, as did social Darwinism as there were theories produced to suggest the white race was genetically superior (where the term Caucasian came from).