Portal:Military of the United States/Selected anniversaries/September 17
- 1778 - Treaty of Fort Pitt signed, the first formal treaty between the United States and a Native American tribe.
- 1862 - American Civil War: George McClellan halts the northward drive of Robert E. Lee's Confederate army in the Battle of Antietam.
- 1894 - Battle of the Yalu River, the largest naval engagement of the First Sino-Japanese War.
- 1900 - Philippine–American War: Filipinos under Juan Cailles defeat Americans under Colonel Benjamin F. Cheatham at Mabitac.
- 1944 - Allied Airborne troops parachute into the Netherlands as half of Operation Market Garden.
- 1947 - James V. Forrestal was sworn in as the first Secretary of Defense of United States.