1863 was a pivotal year, particularly dominated by the American Civil War, but also marked by significant developments in other fields.
Political and Military Events
January 1: Emancipation Proclamation (United States): President Abraham Lincoln issued the Emancipation Proclamation, declaring all slaves in Confederate-held territory to be free. This fundamentally changed the character of the war, transforming it into a struggle for abolition as well as union.
January 1: Rosecrans defeats Bragg at the Battle of Stones River (United States): Following a bloody and strategically inconclusive fight, Union forces under General William Rosecrans forced Confederate forces under General Braxton Bragg to retreat from the Murfreesboro area of Tennessee.
May 1 – May 4: Battle of Chancellorsville (United States): Confederate General Robert E. Lee achieved a brilliant tactical victory against the Union Army of the Potomac, though at the cost of Stonewall Jackson, who was mortally wounded. Despite the Confederate victory, heavy casualties and the loss of Jackson would negatively impact future Confederate operations.
May 14: Siege of Vicksburg begins (United States): Union General Ulysses S. Grant began the siege of Vicksburg, Mississippi, a vital Confederate stronghold on the Mississippi River.
July 1 – July 3: Battle of Gettysburg (United States): Considered a turning point in the American Civil War, the Union Army of the Potomac, under General George Meade, decisively defeated Robert E. Lee's Army of Northern Virginia at Gettysburg, Pennsylvania. This marked the high-water mark of the Confederacy.
July 4: Fall of Vicksburg (United States): After a prolonged siege, Vicksburg surrendered to Union forces, giving the Union control of the entire Mississippi River and effectively splitting the Confederacy in two.
July 9: Fall of Port Hudson (United States): The Confederate garrison at Port Hudson, Louisiana, surrendered to Union forces, completing the Union's control of the Mississippi River.
August 21: Lawrence Massacre (United States): Quantrill's Raiders, a Confederate guerrilla group, attacked and burned the town of Lawrence, Kansas, killing approximately 200 civilians.
September 19 – September 20: Battle of Chickamauga (United States): Confederate General Braxton Bragg defeated Union General William Rosecrans in one of the bloodiest battles of the war.
November 19: Gettysburg Address (United States): President Abraham Lincoln delivered his famous Gettysburg Address at the dedication of the Soldiers' National Cemetery in Gettysburg, Pennsylvania. This concise speech eloquently articulated the principles of human equality espoused by the Declaration of Independence and redefined the purpose of the war as a struggle to preserve a nation "conceived in liberty, and dedicated to the proposition that all men are created equal."
November 23 – November 25: Battle of Chattanooga (United States): Union forces under General Ulysses S. Grant decisively defeated Confederate forces under General Braxton Bragg, opening the way for a Union invasion of the Confederate heartland.
Scientific Events
August 28: The International Red Cross conference in Geneva: The first international conference of the Red Cross met in Geneva. Resulting in the Geneva Convention of 1864.
Cultural Events
March 1: Arizona is organized as a United States Territory: President Abraham Lincoln signed the Act which formally created the Arizona Territory.
Technological Events
First successful compressed air rock drill: Introduced by J.J. Couch, revolutionizing mining and tunneling.
Other Notable Events
June 7: French intervention in Mexico: French troops entered Mexico City to support the establishment of the Second Mexican Empire under Maximilian I.