On December 20, South Carolina secedes from the union, setting in motion the forces leading to the US Civil war.

Southern Secession South Carolina secedes in December. More states follow the next year.

The Pony Express begins cross-country mail delivery.

Abraham Lincoln becomes sixteenth president of the United States.

Fort Sumter shelled, American Civil War begins.

The First Battle of Bull Run, also known as the First Battle of Manassas (the name used by Confederate forces and still often used in the Southern United States), is fought on July 21, 1861, near Manassas, Virginia. It is the first major land battle of the American Civil War. Neither Confederate nor Union troops were ready for battle. Union troops advanced on Confederate troops, almost breaking through, but at the last moment, Confederate reinforcements arrived on the battlefield and carried the day. Union troops were routed. Union civilian spectators, who had come to watch the expected Confederate defeat as entertainment, were forced to run for their lives.

The US flag is modified to have thirty-four stars, reflecting the addition of one new state: Kansas.

United States Civil War Four years of brutal conflict claim 623,000 lives.

Congress passes the First Confiscation Act, which prevents Confederate slave owners from re-enslaving runaways.

On April 16, Congress abolishes slavery in the District of Columbia.

Otto von Bismarck is appointed Prime Minister of Prussia.

The Battle of Fort Donelson (11-16 Feb) is an early Union victory in the American Civil War, which opened the Cumberland River as an avenue for the invasion of the South. The success elevated Brig. Gen. Ulysses S. Grant from an obscure and largely unproven leader to the rank of major general.

The Battle of Shiloh (6-7 Apr). Although the Confederates swept the field on the first day, Union troops under U. S. Grant retook the field on the second day. Combined Union and Confederate casualties (23,746 killed, wounded, or missing) represented more than the total American battle-related casualties of the American Revolutionary War, the War of 1812, and the Mexican-American War combined.

The US flag is modified to have thirty-five stars, reflecting the addition of one new state: West Virginia. This new state was created when Union sympathizers in the western portion of Virginia seceded from Virginia (then in secession from the US) and rejoined the Union.

Abraham Lincoln's Emancipation Proclamation takes effect on January 1, legally freeing slaves in areas of the South still in rebellion against the United States.

The Battle of Gettysburg (1-3 Jul) was the battle with the largest number of casualties in the American Civil War. Union Maj. Gen. George Gordon Meade's Army of the Potomac defeated attacks by Confederate Gen. Robert E. Lee's Army of Northern Virginia, ending Lee's invasion of the North.

The Siege of Vicksburg was the final major military action in the Vicksburg Campaign of the American Civil War. Union Maj. Gen. Ulysses S. Grant crossed the Mississippi River and drove the Confederate army of Lt. Gen. John C. Pemberton into the fortress city of Vicksburg, Mississippi, and placed the city under siege. After more than forty days, with no re-enforcement and supplies nearly gone, the garrison surrendered on July 4. This surrender, combined with Lee's defeat at Gettysburg the previous day, represents the turning point of the war. From then on, military victory for the Confederacy was impossible.

After the Confederate defeat at Chattanooga, President Lincoln promoted Grant to a special regular army rank, Lieutenant General, authorized by Congress on March 2, 1864. This rank had previously been awarded two other times, a full rank to George Washington and a Brevet rank to Winfield Scott. Lincoln then places Grant in charges of all Union forces.

Sherman captures Atlanta, marches to Savannah. Through a series of bloody battles, Grant forces Lee back to Petersburg, Virginia, and then lays siege to the city. Lincoln is reelected, destroying the South's hope for a political settlement to the war.

On February 1, Abraham Lincoln signs the 13th Amendment to the United States Constitution outlawing slavery throughout the United States.

The Thirteenth Amendment to the United States Constitution officially abolished slavery and involuntary servitude, except as punishment for a crime. It was passed by the Senate on April 8, 1864, passed by the House on January 21, 1865, and adopted on December 6, 1865.

Lee surrenders, US Civil war ends, Lincoln assassinated.

Andrew Johnson becomes seventeenth president of the United States.

The US flag is modified to have thirty-six stars, reflecting the addition of one new state: Nevada.

The Ku Klux Klan is formed on December 24 in Polanski, Tennessee, by six Confederate veterans. Nathan Bedford Forrest, a former Confederate cavalry general and slave trader, serves as the Klan's first grand wizard or leader-in-chief.

On June 13, Congress approves the Fourteenth Amendment to the Constitution, guaranteeing due process and equal protection under the law to all citizens. The amendment also grants citizenship to African-Americans.

The US flag is modified to have thirty-seven stars, reflecting the addition of one new state: Nebraska.

The Alaska Purchase resulted in the transfer of Alaska to the United States from the Russian Empire for a total price of $ 7,000,000. The purchase, made at the initiative of United States Secretary of State William H. Seward, gained 586,412 square miles of new United States territory.

The Meiji Restoration in Japan (led by samurai from the western clans of Satsuma, Choshu, Tosa, and Hizen) overthrows the feudal shogunate system and initiates Japan's participation in the modern world.

The Impeachment of Andrew Johnson, 17th President of the United States, was one of the most dramatic events in the political life of the United States during Reconstruction, and the first impeachment in history of a sitting United States president.

On February 26, Congress sends the Fifteenth Amendment to the Constitution to the states for approval. The amendment guarantees African-American males the right to vote.

Transcontinental Rail Service Begun in the United States On May 10th, at Promontory Point, Utah, a golden rail spike was struck, completing the first transcontinental railroad line.

Ulysses S. Grant becomes eighteenth president of the United States.

Japan colonizes Hokkaido as part of its new nation state.

The Suez Canal opened to traffic on 17 November. The canal linked the Mediterranean and the Red Sea. It was 103 miles long and it brought Oriental ports 5,000 miles closer to Europe. Work had begun on the canal in 1859, financed primarily by French investors. The canal increased the strategic importance of Egypt to European powers.