May 24 in Military History

The United Irishmen launched their rebellion against British rule, beginning with risings in Leinster. The uprising, though ultimately crushed, led directly to the Act of Union joining Ireland to Britain.

Samuel Morse transmitted "What hath God wrought" from Washington to Baltimore, demonstrating the telegraph that would revolutionize military communications and transform the conduct of war.

Union forces crossed the Potomac River and occupied the city of Alexandria, Virginia, in one of the first organized military operations of the Civil War. Colonel Elmer Ellsworth was killed by the owner of a secession flag, becoming the first Union officer killed in the conflict.

The Brooklyn Bridge formally opened with a review of U.S. Army, Navy, and New York State National Guard units that marched across the span. The bridge's 1,595-foot main span was the longest in the world, and its engineering innovations shaped later military and civilian bridge construction for a century.

The Second Battle of Ypres in Belgium concluded after five weeks of fighting that saw the first large-scale use of chemical weapons in the war. The battle produced roughly 70,000 Allied and 35,000 German casualties and forced a permanent shift in soldiers' personal protective equipment.

British aviator Amy Johnson landed her de Havilland Gipsy Moth at Fannie Bay aerodrome in Darwin, completing the first solo flight by a woman from England to Australia. The 19-day, 11,000-mile journey demonstrated the long-range capabilities of small aircraft and shaped later military aviation design.

The French port of Boulogne fell to the German 2nd Panzer Division after fierce resistance by Guards regiments, further tightening the noose around the BEF at Dunkirk.

Adolf Hitler issued the order suspending the advance of Army Group A panzer divisions approaching Dunkirk, allowing the British Expeditionary Force and French First Army to establish a defensive perimeter around the port. The decision enabled Operation Dynamo and the evacuation of roughly 338,000 troops over the following nine days.

In the Battle of the Denmark Strait, the Bismarck destroyed HMS Hood in minutes, killing 1,415 of 1,418 crew in one of the Royal Navy's worst disasters.

Grand Admiral Karl Dönitz temporarily withdrew U-boats from the North Atlantic after devastating losses in May, 41 submarines sunk, effectively conceding defeat in the Battle of the Atlantic.

The British frigate HMS Antelope exploded and sank in San Carlos Water when a bomb disposal team attempted to defuse an unexploded Argentine bomb lodged in the ship's engine room.