The concept that the Civil War and Reconstruction period can be called a “Second American Revolution” was firstly introduced by historians (such as Charles A. Beard) in the early 20th century, on the basis that the combat against and subsequent abolition of slavery constituted a radical shift in the country’s socioeconomical and political structures. One of the main arguments supporting this allegation is that the Second American Revolution, by making slavery illegal and guaranteeing civil rights to the newly-freed people through three Constitutional amendments, would extend the right to freedom to all its peoples, therefore complementing the First American Revolution, which gave freedom and independence to a large part (albeit not to the entirety) of the population.