A cause and effect of the Civil War By marea May 3, 1793 Eli Whitney Eli Whitney invented the cotton gin in 1793 May 3, 1860 South Carolina South Carolina Seceddes in 1860 Sep 4, 1860 Fort Sumter The South attacked Fort Sumter at Charleston, South Carolina in 1860. May 3, 1861 Civil War The Civil war started in 1861 May 3, 1865 Civil War ends The civil war ended in 1865