10. The deadliest war in American history, the Civil War was a large-scale rebellion by eleven states of the Union to form a breakaway nation after the election of Abraham Lincoln in 1860
Known contextually as the War of the Rebellion, the American Civil War was fought from 1861 to 1865 between the United States, also known during the conflict as the Union, and the Confederate States: a breakaway group of eleven states, out of the then-thirty-four, who elected to secede from the country and institute a new nation. Declaring their departure following the November 1860 election of Abraham Lincoln, who won office, despite not even appearing on the ballots in many southern states, on a platform opposed to the expansion of slavery into the western territories, Lincoln’s administration responded pronouncing the action an illegal rebellion.
Raising volunteer and conscript armies, the resultant conflict started on April 12, 1861, with the Battle of Fort Sumter. Costing the lives of between 620,000 and 750,000 soldiers – the deadliest war in American history, responsible for more American fatalities than all other conflicts combined – it has been estimated the Civil War claimed the lives of ten percent of all Northern men between the ages of twenty and forty-five as well as thirty percent of all white Southern men between eighteen and forty. Ending with the surrender at Appomattox Court House on April 9, 1865, the nation’s political reintegration would take another twelve years to formally conclude.