Answer:The Civil War in the United States began in 1861, after decades of simmering tensions between northern and southern states over slavery, states' rights and westward expansion. ... The War Between the States, as the Civil War was also known, ended in Confederate surrender in 1865. The Civil War is the central event in America's historical consciousness. While the Revolution of 1776-1783 created the United States, the Civil War of 1861-1865 determined what kind of nation it would be. The war resolved two fundamental questions left unresolved by the revolution: whether the United States was to be a dissolvable confederation of sovereign states or an indivisible nation with a sovereign national government; and whether this nation, born of a declaration that all men were created with an equal right to liberty, would continue to exist as the largest slaveholding country in the world.