The First Red Scare

The word "Red" has long been associated with the Communists and Socialists, while "White" has been associated with the conservatives

Red Scare - a period of general fear of communists

The first in a series of so-called “Palmer Raids” was launched on November 7, 1919 — the second anniversary of the October Revolution in Russia. Thousands of anarchists and communists were rounded up, many of whom were detained for long periods without being formally charged. In December, in a highly publicized move, more than 200 alien detainees were deported to Finland and later to Russia. Placed aboard the Buford, dubbed the “Soviet Ark,” were such prominent leftists as Emma Goldman, the Russian-born anarchist, who had drawn disapproval by opposing the draft and promoting birth control.
 
Despite finding no credible evidence that a communist plot was underway, Palmer staged more raids in January 1920. With the assistance of local law enforcement officials throughout the country, as many as 6,000 suspects were arrested and detained.
 
Palmer claimed to know that May 1, the socialist Labor Day, would bring massive demonstrations as a prelude to revolution. The American public was apprehensive as the date approached, but the predictions proved to be without foundation and Palmer’s standing declined rapidly. He was criticized sharply for conducting searches without warrants and for denying detainees legal representation. Most damning were the charges of some who believed that Palmer had manufactured the crisis as a means to gain the Democratic presidential nomination in 1920.

The events of 1919-1920 were the first of a series of “red scares” in American history in which the government would clamp down on real or imagined domestic revolutionaries.
(http://www.u-s-history.com/pages/h1343.html)