Georgia is a state in the Southeastern region of the United States, bordered to the north by Tennessee and North Carolina; to the northeast by South Carolina; to the southeast by the Atlantic Ocean; to the south by Florida; and to the west by Alabama. Georgia is the 24th-largest in area and 8th-most populous of the 50 United States. Its 2020 population was 10,711,908, according to the U.S. Census Bureau. Atlanta, a "beta(+)" global city, is both the state's capital and its largest city. The Atlanta metropolitan area, with a population of more than 6 million people in 2020, is the 9th most populous metropolitan area in the United States and contains about 57% of Georgia's entire population.Founded in 1732 as the Province of Georgia and becoming a royal colony in 1752, Georgia was the last and southernmost of the original Thirteen Colonies to be established. Named after King George II of Great Britain, the Colony of Georgia covered the area from South Carolina south to Spanish Florida and west to French Louisiana at the Mississippi River. On January 2, 1788, Georgia became the fourth state to ratify the United States Constitution. From 1802 to 1804, western Georgia was split to form the Mississippi Territory, which later was admitted as the U.S. states of Alabama and Mississippi. Georgia declared its secession from the Union on January 19, 1861, and was one of the original seven Confederate States. Following the Civil War, it was the last state to be restored to the Union, on July 15, 1870. In the post-Reconstruction era of the late 19th century, Georgia's economy was transformed as a group of prominent politicians, businessmen, and journalists, led by Henry W. Grady, espoused the "New South" philosophy of sectional reconciliation, industrialization, and white supremacy. During the mid-20th century, several Georgians, most notably Martin Luther King Jr., were prominent leaders during the civil rights movement. Atlanta was selected as host of the 1996 Summer Olympics, which marked the 100th anniversary of the modern Olympic Games. Since 1945, Georgia has seen substantial population and economic growth as part of the broader Sun Belt phenomenon. From 2007 to 2008, 14 of Georgia's counties ranked among the nation's 100 fastest-growing.Georgia is defined by a diversity of landscapes, flora, and fauna. The state's northernmost regions include the Blue Ridge Mountains, part of the larger Appalachian Mountain system. The Piedmont plateau extends from the foothills of the Blue Ridge south to the Fall Line, an escarpment to the Coastal Plain defining the state's southern region. Georgia's highest point is Brasstown Bald at 4,784 feet (1,458 m) above sea level; the lowest is the Atlantic Ocean. With the exception of some high-altitude areas in the Blue Ridge, the entirety of the state has a humid subtropical climate. Of the states entirely east of the Mississippi River, Georgia is the largest in land area.

The American Civil War (April 12, 1861 – May 9, 1865; also known by other names) was a civil war in the United States between the Union (states that remained loyal to the federal union, or "the North") and the Confederacy (states that voted to secede, or "the South"). The central cause of the war was the status of slavery, especially the expansion of slavery into territories acquired as a result of the Louisiana Purchase and the Mexican–American War. On the eve of the Civil War in 1860, four million of the 32 million Americans (~13%) were enslaved black people, almost all in the South.The practice of slavery in the United States was one of the key political issues of the 19th century. Decades of political unrest over slavery led up to the Civil War. Disunion came after Abraham Lincoln won the 1860 United States presidential election on an anti-slavery expansion platform. An initial seven southern slave states declared their secession from the country to form the Confederacy. Confederate forces seized federal forts within territory they claimed. The last-minute Crittenden Compromise tried to avert conflict but failed; both sides prepared for war. Fighting broke out in April 1861 when the Confederate army began the Battle of Fort Sumter in South Carolina, just over a month after the first inauguration of Abraham Lincoln. The Confederacy grew to control at least a majority of territory in eleven states (out of the 34 U.S. states in February 1861), and asserted claims to two more. Both sides raised large volunteer and conscription armies. Four years of intense combat, mostly in the South, ensued.

During 1861–1862 in the war's Western Theater, the Union made significant permanent gains—though in the war's Eastern Theater the conflict was inconclusive. On January 1, 1863, Lincoln issued the Emancipation Proclamation, which made ending slavery a war goal, declaring all persons held as slaves in states in rebellion "forever free." To the west, the Union destroyed the Confederate river navy by the summer of 1862, then much of its western armies, and seized New Orleans. The successful 1863 Union siege of Vicksburg split the Confederacy in two at the Mississippi River. In 1863, Confederate General Robert E. Lee's incursion north ended at the Battle of Gettysburg. Western successes led to General Ulysses S. Grant's command of all Union armies in 1864. Inflicting an ever-tightening naval blockade of Confederate ports, the Union marshaled resources and manpower to attack the Confederacy from all directions. This led to the fall of Atlanta in 1864 to Union General William Tecumseh Sherman and his march to the sea. The last significant battles raged around the ten-month Siege of Petersburg, gateway to the Confederate capital of Richmond.

The Civil War effectively ended on April 9, 1865, when Confederate General Lee surrendered to Union General Grant at the Battle of Appomattox Court House, after Lee had abandoned Petersburg and Richmond. Confederate generals throughout the Confederate army followed suit. The conclusion of the American Civil War lacks a clean end date: land forces continued surrendering until June 23. By the end of the war, much of the South's infrastructure was destroyed, especially its railroads. The Confederacy collapsed, slavery was abolished, and four million enslaved black people were freed. The war-torn nation then entered the Reconstruction era in a partially successful attempt to rebuild the country and grant civil rights to freed slaves.

The Civil War is one of the most studied and written about episodes in the history of the United States. It remains the subject of cultural and historiographical debate. Of particular interest is the persisting myth of the Lost Cause of the Confederacy. The American Civil War was among the earliest to use industrial warfare. Railroads, the telegraph, steamships, the ironclad warship, and mass-produced weapons saw wide use. In total the war left between 620,000 and 750,000 soldiers dead, along with an undetermined number of civilian casualties. President Lincoln was assassinated just five days after Lee's surrender. The Civil War remains the deadliest military conflict in American history. The technology and brutality of the Civil War foreshadowed the coming World Wars.