The National Defense Act is signed into law, increasing the size of the United States National Guard by 450,000 men.

The National Defense Act of 1916, Pub. L. 64–85, 39 Stat. 166, enacted June 3, 1916, was a United States federal law that updated the Militia Act of 1903, which related to the organization of the military, particularly the National Guard. The principal change of the act was to supersede provisions…