50,000 U.S. combat troops under the command of Lieutenant General Simon B. Buckner Jr., land on the southwest coast of the Japanese island of Okinawa.

Because it lacked sufficient funds to build a strong navy, the Continental Congress gives privateers permission to attack any and all British ships on April 3, 1776.

The Rebel capital of Richmond, Virginia, falls to the Union, the most significant sign that the Confederacy is nearing its final days.

On April 3, the first Pony Express mail, traveling by horse and rider relay teams, simultaneously leaves St. Joseph, Missouri, and Sacramento, California.

Just after 6 p.m., Martin Luther King, Jr. is fatally shot while standing on the balcony outside his second-story room at the Lorraine Motel in Memphis, TN. The civil rights leader was 39 years old.

Battle between the Sauk tribe led by Black Hawk and the United States in the area around Rock River in Illinois.

The GAR, an American patriotic organization composed of Union veterans of the American Civil War is founded. It lasts until 1956.

The Civil War explodes in the west as the armies of Union General Ulysses S. Grant and Confederate General Albert Sidney Johnston collide at Shiloh, near Pittsburgh Landing in Tennessee.

Two days after the U.S. Senate voted 82 to 6 to declare war against Germany, the U.S. House of Representatives endorses the declaration by a vote of 373 to 50, and America formally enters World War I.

In Appomattox Court House, Virginia, Confederate General Robert E. Lee surrenders his 28,000 troops to Union General Ulysses S. Grant, effectively ending the American Civil War.

The American Third Army liberates the Buchenwald concentration camp, near Weimar, Germany, a camp that will be judged second only to Auschwitz.

Confederate General P.G.T. Beauregard opens fire on Union-held Fort Sumter in South Carolina's Charleston Bay.

On April 18, 1942, 16 American B-25 bombers, launched from the aircraft carrier USS Hornet 650 miles east of Japan and commanded by Lieutenant Colonel James H. Doolittle, attack the Japanese mainland.

On April 27, 1865, the steamboat Sultana explodes on the Mississippi River near Memphis, killing 1,700 passengers including many discharged Union soldiers.

On April 29, 1945, the U.S. Seventh Army’s 45th Infantry Division liberates Dachau, the first concentration camp established by Germany’s Nazi regime.

The South Vietnamese stronghold of Saigon (now known as Ho Chi Minh City) falls to People's Army of Vietnam and the Viet Cong on April 30, 1975.