| 105361 | September 15 | Event | 1812 – War of 1812: A second supply train sent to relieve Fort Harrison is ambushed in the Attack at the Narrows. |
| 105362 | September 15 | Event | 1816 – HMS Whiting runs aground on the Doom Bar |
| 105363 | September 15 | Event | 1820 – Constitutionalist revolution in Lisbon, Portugal. |
| 105364 | September 15 | Event | 1821 – Guatemala, El Salvador, Honduras, Nicaragua, and Costa Rica jointly declare independence from Spain. |
| 105365 | September 15 | Event | 1830 – The Liverpool to Manchester railway line opens. |
| 105366 | September 15 | Event | 1831 – The locomotive John Bull operates for the first time in New Jersey on the Camden and Amboy Railroad. |
| 105367 | September 15 | Event | 1835 – HMS Beagle, with Charles Darwin aboard, reaches the Galápagos Islands. The ship lands at Chatham or San Cristobal, the easternmost of the archipelago. |
| 105368 | September 15 | Event | 1851 – Saint Joseph's University is founded in Philadelphia, Pennsylvania. |
| 105369 | September 15 | Event | 1862 – American Civil War: Confederate forces capture Harpers Ferry, Virginia. |
| 105370 | September 15 | Event | 1873 – Franco-Prussian War: The last German troops leave France upon completion of payment of indemnity. |
| 105371 | September 15 | Event | 1894 – First Sino-Japanese War: Japan defeats Qing dynasty China in the Battle of Pyongyang. |
| 105372 | September 15 | Event | 1915 – The Empire Picture Theatre (now The New Empire Cinema), the oldest running Cinema in Mainland Australia, opens in Bowral, New South Wales. |
| 105373 | September 15 | Event | 1916 – World War I: Tanks are used for the first time in battle, at the Battle of the Somme. |
| 105374 | September 15 | Event | 1918 – World War I:The Battle of Dobro Pole is fought, Entente troops break through the Bulgarian defenses on the Macedonian Front eventually liberating Vardar Macedonia and forcing Bulgaria to sign the Armistice of Salonica. |
| 105375 | September 15 | Event | 1935 – The Nuremberg Laws deprive German Jews of citizenship. |
| 105376 | September 15 | Event | 1935 – Nazi Germany adopts a new national flag bearing the swastika. |
| 105377 | September 15 | Event | 1940 – World War II: The climax of the Battle of Britain, when the Royal Air Force shoots down large numbers of Luftwaffe aircraft. |
| 105378 | September 15 | Event | 1942 – World War II: U.S. Navy aircraft carrier USS Wasp is sunk by a Japanese torpedo at Guadalcanal. |
| 105379 | September 15 | Event | 1944 – Franklin D. Roosevelt and Winston Churchill meet in Quebec as part of the Octagon Conference to discuss strategy. |
| 105380 | September 15 | Event | 1944 – Battle of Peleliu begins as the United States Marine Corps' 1st Marine Division and the United States Army's 81st Infantry Division hit White and Orange beaches under heavy fire from Japanese infantry and artillery. |
| 105381 | September 15 | Event | 1945 – A hurricane in southern Florida and the Bahamas destroys 366 planes and 25 blimps at Naval Air Station Richmond. |
| 105382 | September 15 | Event | 1947 – RCA releases the 12AX7 vacuum tube. |
| 105383 | September 15 | Event | 1947 – Typhoon Kathleen hit the Kanto Region in Japan killing 1,077. |
| 105384 | September 15 | Event | 1948 – The F-86 Sabre sets the world aircraft speed record at 671 miles per hour (1,080 km/h). |
| 105385 | September 15 | Event | 1950 – Korean War: United States forces land at Inchon |
| 105386 | September 15 | Event | 1952 – The United Nations cedes Eritrea to Ethiopia. |
| 105387 | September 15 | Event | 1958 – A Central Railroad of New Jersey commuter train runs through an open drawbridge at the Newark Bay, killing 48. |
| 105388 | September 15 | Event | 1959 – Nikita Khrushchev becomes the first Soviet leader to visit the United States. |
| 105389 | September 15 | Event | 1961 – Hurricane Carla strikes Texas with winds of 175 miles per hour. |
| 105390 | September 15 | Event | 1962 – The Soviet ship Poltava heads toward Cuba, one of the events that sets into motion the Cuban Missile Crisis. |