Colonel Robert E. Lee resigned his commission in the United States Army, two days after declining an offer to command the Union forces. He joined the Confederacy, becoming its most celebrated general. His decision split the Army's officer corps and prolonged the Civil War.
Colonel Robert E. Lee resigned his commission in the United States Army after declining command of the Union forces. He joined the Confederacy, becoming its most celebrated general.
President Ulysses S. Grant signed the Third Enforcement Act, also known as the Ku Klux Klan Act, authorizing the use of federal troops to suppress KKK violence in the South. It was the first federal law specifically targeting domestic terrorism.
Elements of the U.S. Third and Seventh Armies completed the capture of Nuremberg after four days of urban combat. American troops raised the Stars and Stripes over the Nazi Party Rally Grounds on Hitler's 56th birthday.
Lead elements of the Soviet 3rd Shock Army and 1st Guards Tank Army reached the northeastern and eastern outskirts of Berlin, beginning the urban assault on the German capital.
NASA's Surveyor 3 soft-landed in the Ocean of Storms, returning the first trench-digging and soil-mechanics data from the lunar surface. Thirty-one months later, Apollo 12 astronauts Pete Conrad and Alan Bean walked 600 feet from their LM to Surveyor 3 and returned parts of the probe, yielding the first long-duration materials data from a spacecraft exposed to lunar environment.
Navy Captain John Young and Charles Duke landed the lunar module Orion in the Descartes Highlands, beginning the fifth crewed lunar landing and the first dedicated to geological exploration of lunar highlands terrain.
Two students killed 13 people and wounded 24 others at Columbine High School in Littleton, Colorado, before taking their own lives. The massacre prompted major changes to law enforcement tactical response protocols nationwide.
NATO aircraft struck the Radio Television of Serbia broadcast complex and multiple command and control nodes in Belgrade, attempting to degrade the Milosevic government's ability to direct Serbian military operations in Kosovo.
The Transocean Deepwater Horizon drilling rig exploded in the Gulf of Mexico, killing 11 workers and triggering the largest marine oil spill in U.S. history. U.S. Coast Guard response and later Department of Defense support operations ran for months.
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Lieutenant General
Known as the "father of modern amphibious warfare," he commanded Marine forces in the Pacific during WWII. He led the assaults on Tarawa, Saipan, Tinian, and Iwo Jima.
Gefreiter (Lance Corporal)
WWI veteran who served as a dispatch runner on the Western Front, receiving the Iron Cross First Class. He later became dictator of Nazi Germany and instigated WWII, causing the deaths of tens of millions.
Author
Irish author best known for the Gothic horror novel Dracula. While not a military figure, his portrayal of Van Helsing's strategic campaign against Dracula drew on contemporary military planning concepts.
War Chief
Ottawa war chief who led Pontiac's Rebellion (1763-1766), a confederation of Native American tribes that captured eight British forts in the Great Lakes region. His resistance shaped British colonial policy and led to the Proclamation of 1763.
10 military events occurred on April 20, spanning multiple centuries. Key events include: Robert E. Lee Resigns from the US Army (1861), Norfolk Navy Yard Destroyed (1861).
The most significant military event on April 20 is Robert E. Lee Resigns from the US Army (1861). Colonel Robert E. Lee resigned his commission in the United States Army, two days after declining an offer to command the Union forces. He joined the Confederacy, becoming its most celebrated general. His decision split the Army's officer corps and prolonged the Civil War.
Notable military figures born on April 20 include Holland "Howlin' Mad" Smith (1882–1967), Adolf Hitler (1889–1945).
Events on April 20 span the Civil War, the Modern Era, World War II, the Cold War, covering 10 events across 3 centuries of military history.
Events on April 20 involve 5 branches of the U.S. and allied armed forces, reflecting the global scope of military operations throughout history.
Explore military history from the day you were born.
June 6
The Allied invasion of Normandy, the largest amphibious assault in history.
December 7
Japan attacks the U.S. Pacific Fleet, bringing America into World War II.
September 11
The deadliest terrorist attack in history transforms U.S. national security.
August 6
The first atomic bomb is dropped on a city, ushering in the nuclear age.
May 8
Nazi Germany surrenders unconditionally, ending World War II in Europe.
November 11
Armistice Day marks the end of World War I and honors all who served.
June 4
The turning point of the Pacific War as the U.S. Navy destroys four Japanese carriers.
July 4
The Declaration of Independence is adopted, sparking the American Revolution.
The FIM-92 Stinger helped win the Cold War by turning Afghan mujahideen into a credible anti-aircraft threat. By 2023, the United States almost ran out of them, because Raytheon stopped making them for 13 years, and the first 10 months of Ukraine support burned through the remaining stockpile.
Amateurs study tactics. Professionals study logistics. The most quoted military truism is also the most ignored. From WWII's industrial avalanche to Russia's 40-mile traffic jam in Ukraine, every major conflict proves the same lesson, and the U.S. military's just-in-time supply model may not survive a real fight.
Eighteen inches. At 400 mph. The margin for error is less than the length of your forearm. How the Blue Angels and Thunderbirds train their pilots to fly in formation so tight that one flinch would be catastrophic, and why the military considers air show teams a combat-relevant mission.
More service members are injured in training than in most deployments. From the simulated POW camps of SERE school to the controlled chaos of a carrier flight deck, these 10 exercises push human limits harder than many actual combat missions.
