On April 24, 1915, the German army used chlorine gas against Canadian troops at Ypres. Gas was later employed by British and French forces against the Germans. Learn more about early efforts by the Red Cross to ban chemical weapons and review the June 1925 Protocol for the Prohibition of the Use in War of Asphyxiating, Poisonous or other Gases and of Bacteriological Methods of Warfare.

On April 24, 1800, US President John Adams approved $5,000 to fund the establishment of the US Library of Congress. Learn more about the history of the US Library of Congress.