(Friday, May 18, 1917; during World War I) — U.S. President Woodrow Wilson today signed the Selective Service Act of 1917, which gave him the power to conscript men ages 21 to 30 and the option of calling up 500,000 volunteers.

Wilson also announced he would allow no special volunteer divisions in the war, denying a request by former President Theodore Roosevelt to form a new version of his Rough Riders, the all-volunteer division that he’d led in the Spanish-American War.

Wilson, who met Roosevelt at the White House on Apr. 10, 1917, sent the former president a telegram today, claiming he’d based his decision on “imperative considerations of public policy and not upon personal or private choice.”