The American Civil War took place from 1861 to 1865, primarily between the northern states, known as the Union, and the southern states, known as the Confederacy. The war was largely fought over issues such as slavery, states' rights, and economic differences. It resulted in significant loss of life and property, with an estimated 620,000 to 750,000 soldiers dying in battle or from disease. The conflict began with the Battle of Fort Sumter in April 1861 and included major battles like Gettysburg and Antietam. The war ended with the surrender of General Robert E. Lee at Appomattox Court House in April 1865. The aftermath led to the Reconstruction Era, which aimed to rebuild the South and integrate formerly enslaved people into society.