an expert in or student of history, especially that of a particular period, geographical region, or social phenomenon.
historian
a crop produced for its commercial value rather than for use by the grower.
cash crops
an artifact, document, diary, manuscript, autobiography, recording, or any other source of information that was created at the time under study.
primary source
sign or give formal consent to (a treaty, contract, or agreement), making it officially valid
ratify
withdraw from commercial or social relations with (a country, organization, or person) as a punishment or protest.
botcott
to officially make (a law) no longer valid
repeal
the act or an instance of killing a number of usually helpless or innocent human beings
massacre
information, especially of a biased or misleading nature, used to promote or publicize a particular political cause or point of view
propaganda