The play 'Why Marry?' opened at the Astor Theatre in New York City.
Finland declared its independence from the Russian Empire.
41 Suffragists were arrested at the White House, Washington, D.C.
American suffragist Alice Paul was sentenced to seven months in prison for obstructing traffic in Washington caused by the Women's Rights march she organized.
Dutch exotic dancer Mata Hari was put on trial in Paris after being accused of being a spy.
The British Royal family changed their surname to Windsor.
Several internal explosions inside Britain's HMS Vanguard battleship occurred at Scapa Flow, Orkney Islands, Scotland.
Registration of US men aged between 21 and 31 began for troops for WWI.
Baseball and war hero Hank Gowdy became the first player to enlist in the US Army during World War II.
The US Congress passed Selective Service Act.
Eugene Bullard became the first African-American military pilot after acquiring his pilot's license from the Aéro-Club de France.
The US declared war against Germany and its Central Powers Alliance in World War I.
US President Woodrow Wilson announced that the nation would officially cut relations with Germany.
