April 9 in Military History

General Lee surrendered to General Grant at the McLean House in Appomattox, effectively ending the Civil War. Grant's generous terms set the tone for reconciliation.

The day after his disaster at Mansfield, Union Major General Nathaniel Banks held ground at Pleasant Hill against renewed Confederate attacks under Richard Taylor. The tactical Union victory could not save the Red River Campaign, and Banks ordered a general retreat that night toward the gunboat flotilla trapped in falling water levels.

All four divisions of the Canadian Corps attacked together for the first time, storming the heavily fortified German positions on Vimy Ridge near Arras, France. The battle, which cost 10,602 Canadian casualties, became a defining moment of Canadian national identity.

Germany launched Operation Weserubung, simultaneously invading Denmark and Norway to secure access to Swedish iron ore. Denmark surrendered within six hours; Norway resisted for two months before capitulating.

Norwegian coastal batteries at the 19th-century Oscarsborg fortress sank the new German heavy cruiser Blucher in the narrows of Oslofjord using 11-inch Krupp guns and torpedoes. The sinking delayed Oslo's capture long enough for the Norwegian royal family and government to escape, preserving Norwegian legitimacy for the campaign ahead.

Approximately 76,000 American and Filipino troops surrendered on the Bataan Peninsula, the largest American surrender since the Civil War. The prisoners were then forced on a brutal 66-mile march to POW camps in which thousands died.

Aircraft from the escort carrier USS Guadalcanal and four destroyer escorts sank the German submarine U-515, capturing her commander and 43 crew, part of the hunter-killer campaign that broke the U-boat threat in the Atlantic.

The 3rd Belorussian Front completed a four-day storming of the East Prussian fortress city of Konigsberg, overwhelming German defenders with massed T-34-85 tanks, IS-2 heavy assault guns, and ground-attack aviation. The surrender of the city removed the last significant German holdout in the Baltic and secured the Soviet northern flank for the Berlin operation.

British Eighth Army and U.S. Fifth Army launched Operation Grapeshot, the final Allied offensive in the Italian theater. The 10th Mountain Division spearheaded the American attack across the Apennines toward the Po Valley, using specialized Weasel tracked carriers and mule transport to overcome rugged terrain.

NASA Administrator T. Keith Glennan introduced the Mercury Seven, the first group of American astronauts selected for Project Mercury. All seven were active-duty military test pilots drawn from the Navy, Marines, and Air Force, and their selection established the template for U.S. human spaceflight during the Cold War.

U.S. Marines used an M88 armored recovery vehicle to topple a bronze statue of Saddam Hussein in Baghdad's Firdos Square. The iconic images of the falling statue became the defining visual symbol of the regime's collapse.