the Civil War that began on April 12, 1861, and ended on May 26, 1865, in the United States; The Union, also known as "the North," and the Confederacy, also known as "the South," which consisted of states that had separated from the Union, fought each other during the civil war in the United States. The primary factor that contributed to the outbreak of war was the dispute over whether slavery should be allowed to spread into the western territories, creating additional slave states, or prevented from doing so, which, according to popular belief, would put slavery on the verge of extinction. The political debate over slavery came to a head after decades when Abraham Lincoln, who had opposed slavery's expansion into the western territories, won the 1860 U.S. presidential election. Seven southern slave states formed the Confederacy in February 1861 in response to Lincoln's victory and separated from the United States. The Confederacy seized U.S. forts and other federal property within their borders. In eleven of the 34 states that were in existence at the time, the Confederacy, led by Confederate President Jefferson Davis, established control over approximately a third of the population. Four years of intense fighting followed, the majority of which took place in the South. Between 1861 and 1862, the conflict in the Eastern Theater was unsuccessful, despite the Union's significant permanent gains in the Western Theater. On January 1, 1863, Lincoln gave the Liberation Announcement, which proclaimed that all slaves in states tormented by defiance would be liberated. This included more than 3.5 million of the 4 million people in the country who were enslaved. Former slaves who either escaped from plantations or were freed by the Union Army made up the United States Colored Troops regiments of the Union Army. The Union had taken New Orleans, the Confederacy had lost most of its western armies, and the river navy to its west had been destroyed by summer 1862. After the successful Union siege of Vicksburg in 1863, the Confederacy was split in two at the Mississippi River. Confederate General Robert E. Lee's northward incursion came to an end at the Battle of Gettysburg in 1863. As a result of victories in the West, General Ulysses S. Grant took command of all Union armies in 1864. As it imposed an ever-increasing naval blockade on Confederate ports, the Union gathered men and resources to attack the Confederacy from all sides. Union General William Tecumseh Sherman was successful in capturing Atlanta and marching to the sea in 1864. He was able to win the battle due to this. During the ten-month Siege of Petersburg, which prevented access to Richmond, the Confederacy's capital, the final significant battles took place. Lee gave in to Grant on April 9, 1865, after the Confederates had left Richmond and won the Battle of Appomattox Court House. The war officially began at this point. A flurry of Confederate surrenders followed. On April 14, just five days after Lee surrendered, Lincoln was killed. Although the end of the American Civil War does not have a specific historical date, the surrender of the Department of the Trans-Mississippi on May 26 technically marked the end of the war. After the May 26 deadline, Confederate ground forces surrendered up until June 23. By the end of the war, most of the South's infrastructure, especially its railroads, had been destroyed. After the Confederacy broke up and slavery was made illegal, four million black people who had been enslaved were freed. Following the war, the nation
entered the Reconstruction era with the goals of rebuilding, reuniting the Confederate states, and granting civil rights to freed slaves. The Civil War is one of the periods in American history that has received the most writing and research. It still dominates discussions of culture and history. Particularly intriguing is the persistent legend of the Confederate Lost Cause. The American Civil War was the first time industrial warfare was used. The war made frequent use of steamships, railroads, the ironclad warship, mass-produced weapons, and steamships. Between 620,000 and 750,000 soldiers and an unknown number of civilians were killed in the Civil War, making it the deadliest military conflict in American history[g]. The technology and brutality of the war hinted at the upcoming World Wars.