American Civil War (1861): Improvised armies

About 620,000-850,000 people died, scholarly range -- more US dead than in the two world wars combined for American forces. Industrial railroads, rifled muskets, and a Union naval blockade made it a modern war on a continental map. Gettysburg (1-3 July 1863) and Vicksburg (4 July 1863) were the twin hinges; Appomattox (9 April 1865) ended the main Confederate army.

The 13th, 14th and 15th Amendments recast the Constitution. Reconstruction (1865-77) was a second political war that white supremacist "Redemption" later rolled back. English-speaking memory outside the US treats this as the great American epic; inside the US it remains a live argument about flags, statues and school books.

Union, emancipation and an industrial republic The Civil War was a political war about a slaveholding republic that became, through arms and amendments, a different constitution -- then a contested memory. Lincoln's 1860 election, without southern electoral votes, triggered secession conventions. The Confederate constitution explicitly protected slavery. Sumter forced the upper South to choose; Virginia's departure put the war's capital pair -- Washington and Richmond -- a hundred miles apart.