Originally outlined by Karl Marx and Friedrich Engels in The Communist Manifesto (1848), Communism is a social and political system in which all property is owned communally and all wealth distributed among citizens according to need. Although it was a product of large-scale industrialization in the nineteenth century, Communism has had a profound influence on the global politics and economics of the twentieth century. In the United States, Communism became popular among American industrial workers during the Depression, and played a more public role in politics during the 1930s. In the 1940s and during the Cold War, the treatment of Communist groups and individuals within the United States sometimes raised questions about the fairness not only of the American justice system, but of the Constitution itself.

Communism is most often associated with the revolution which took place in Russia in November 1917, and the establishment of the federalist Soviet Union...