January 16 - The U.S. Senate votes against joining the League of Nations.
January 16 - The 18th U.S. Constitutional Amendment (prohibiting alcohol) goes into effect and will later be the only Amendment to be repealed.
January 31 - The Ukrainian Daily News is the first Ukrainian newspaper published in the U.S.
March 1 - The Supreme Court finds that the large corporation is not an illegal monopoly.
March 19 - The U.S. Senate rejects the Treaty of Versailles.
March 30 - The Julliard Music Foundation is established.
April 13 - Helen Hamilton is appointed the first woman U.S. Civil Service Commissioner.
May 15 - The Tomb of the Unknown Soldier is dedicated at Arlington National Cemetery.
August 26 - Under the 19th Amendment of the U.S. Constitution, women receive the right to vote.
September 28 - Eight players of the Chicago White Sox are indicted for throwing the 1919 World Series between their team and the Cincinnati Reds.
November 2 - Warren G. Harding becomes the 29th U.S. President.
November 2 - The first radio station in the U.S., KDKA of Pittsburgh, Pennsylvania, begins regular broadcasting.
November 12 - - Judge Keneshaw Mountain Landis is appointed the first Commissioner of Baseball. He will hold the position for many years and will rule over policy for all the teams of both the National and American Leagues with a czar-like power.
November 16 - The first postage stamp meter is set in Stamford, Connecticut.
December 18 - The first U.S postage stamps printed without the words United States or the initials U.S. are issued.
