Well, the major reason was that Oliver Cromwell was not a monarch, he did not rule as a King. Cromwell came to the throne after leading a rebellion against the monarchy and was then invited by his fellow leaders to be the lord protector of England.
In the postwar era, African Americans worked to balance their fight for democracy during the war with the unequal traditions at home. They fought for full equality, desegregation, civil and political rights and increased presence in American society.