April 19 in Military History

British regulars and colonial militia exchanged fire at Lexington and Concord, Massachusetts, beginning the American Revolutionary War. The "shot heard round the world" launched the fight for American independence.

The U.S. Army's 1st Division, the first American ground force sent to Europe in World War I, received orders to prepare for overseas movement to France under the newly designated American Expeditionary Forces.

Jewish resistance fighters in the Warsaw Ghetto launched an armed uprising against Nazi German forces attempting to deport the remaining ghetto population to Treblinka. The fighters held out for nearly a month against vastly superior German forces.

General Douglas MacArthur, recently relieved of command by President Truman, delivered his famous farewell address to a joint session of Congress, ending with the iconic words "Old soldiers never die; they just fade away."

Royal Navy frogman Commander Lionel Crabb disappeared while conducting an intelligence dive on the Soviet cruiser Ordzhonikidze in Portsmouth harbor during Khrushchev's state visit. The incident caused a major diplomatic crisis.

President Eisenhower authorized the final U-2 reconnaissance flight over the Soviet Union before the scheduled summit with Khrushchev, the mission that would end in disaster when Powers' aircraft was shot down on May 1.

The Soviet Union launched Salyut 1 from Baikonur Cosmodrome, the world's first space station. Though officially a civilian science program, Salyut emerged from the military Almaz reconnaissance station program and established orbital infrastructure that shaped both Soviet and American military space doctrine through the 1980s.

An explosion in the center gun of Turret Two aboard USS Iowa during a gunnery exercise off Puerto Rico killed 47 sailors. A Sandia National Laboratories reinvestigation later cleared the sailor initially blamed by the Navy.

A truck bomb destroyed the Alfred P. Murrah Federal Building in Oklahoma City, killing 168 people including 19 children. Domestic terrorist and Gulf War veteran Timothy McVeigh was convicted and executed for the attack.

The 1st Marine Expeditionary Force suspended offensive operations in Fallujah after three weeks of urban combat and began a handover to the improvised Fallujah Brigade. The ceasefire would collapse within months, leading to the larger Operation Phantom Fury in November.