This submission has been removed because it violates our '20-Year Rule'. To discourage off-topic discussions of current events, questions, answers and all other comments must be confined to events that happened 20 years ago or more.

We talking world politics or strictly American here?

If we are talking American politics you probably already have an idea about how it affected Americans what with the years of Jim Crow laws, racism, civil rights movements etc.

Could you please clarify, do you mean 20th century (i.e. from 1900-1999) or 21st century (from 2000-2015)?