An oligarchy is the form of government which is rule by few form and that few people may be military control, or by wealthy society or through ethnic identities.
James Madison was the one who became President in the future after writing The federalist papers. Alexander Hamilton, James Madison and John Jay were the three who wrote The federalist papers.
An interest group is an organization whose members share common concerns and try to influence government policies affecting those concerns. Interest groups are also known as lobbies.