The Civil War began in 1861 with the Confederate attack on Fort Sumter and lasted until 1865, involving many major battles such as Antietam, Gettysburg, and in Georgia, Chickamauga and Sherman's March to the Sea which helped turn the tide in favor of the Union. Key events included the Union blockade of Southern ports, the Emancipation Proclamation freeing slaves, and Lee's defeat at Gettysburg which marked a turning point.