Registration of US men aged between 21 and 31 began for troops for WWI.
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President Woodrow Wilson issued a Proclamation of Neutrality.
Germany and its World War I allies become the first countries to use daylight saving time (DST).
Third Battle of Ypres begins in Flanders
The US National Advisory Committee for Aeronautics was founded as an emergency measure during WWI.
The US declared war against Germany and its Central Powers Alliance in World War I.
