The first <a href="https://en.wikipedia.org/wiki/Palmer_Raids" id="mw8g" rel="mw:WikiLink" title="Palmer Raids">Palmer Raid</a> is conducted on the second anniversary of the <a href="https://en.wikipedia.org/wiki/Russian_Revolution" id="mw8w" rel="mw:WikiLink" title="Russian Revolution">Russian Revolution</a>. Over 10,000 suspected communists and anarchists are arrested in 23 U.S. cities.