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 election of Abraham Lincoln in 1860 caused seven southern states to secede and form the Confederate States of America; four more states soon joined them. The War Between the States, as the Civil War was also known, ended in Confederate surrender in 1865. The conflict was the costliest and deadliest war ever fought on American soil, with some 620,000 of 2.4 million soldiers killed, millions more injured and much of the South left in ruin.

Causes of the Civil War

In the mid-19th century, while the United States was experiencing an era of tremendous growth, a fundamental economic difference existed between the country’s northern and southern regions.

In the North, manufacturing and industry was well established, and agriculture was mostly limited to small-scale farms, while the South’s economy was based on a system of large-scale farming that depended on the labor of Black enslaved people to grow certain crops, especially cotton and tobacco.

Growing abolitionist sentiment in the North after the 1830s and northern opposition to slavery’s extension into the new western territories led many southerners to fear that the existence of slavery in America—and thus the backbone of their economy—was in danger.

In 1854, the U.S. Congress passed the Kansas-Nebraska Act, which essentially opened all new territories to slavery by asserting the rule of popular sovereignty over congressional edict. Pro- and anti-slavery forces struggled violently in “Bleeding Kansas,” while opposition to the act in the North led to the formation of the Republican Party, a new political entity based on the principle of opposing slavery’s extension into the western territories. After the Supreme Court’s ruling in the Dred Scott case (1857) confirmed the legality of slavery in the territories, the abolitionist John Brown’s raid at Harper’s Ferry in 1859 convinced more and more southerners that their northern neighbors were bent on the destruction of the “peculiar institution” that sustained them. Abraham Lincoln’s election in November 1860 was the final straw, and within three months seven southern states–South Carolina, Mississippi, Florida, Alabama, Georgia, Louisiana and Texas–had seceded from the United States.

Outbreak of the Civil War (1861)

Even as Lincoln took office in March 1861, Confederate forces threatened the federal-held Fort Sumter in Charleston, South Carolina. On April 12, after Lincoln ordered a fleet to resupply Sumter, Confederate artillery fired the first shots of the Civil War. Sumter’s commander, Major Robert Anderson, surrendered after less than two days of bombardment, leaving the fort in the hands of Confederate forces under Pierre G.T. Beauregard. Four more southern states–Virginia, Arkansas, North Carolina and Tennessee –joined the Confederacy after Fort Sumter. Border slave states like Missouri, Kentucky and Maryland did not secede, but there was much Confederate sympathy among their citizens.

Though on the surface the Civil War may have seemed a lopsided conflict, with the 23 states of the Union enjoying an enormous advantage in population, manufacturing (including arms production) and railroad construction, the Confederates had a strong military tradition, along with some of the best soldiers and commanders in the nation. They also had a cause they believed in: preserving their long-held traditions and institutions, chief among these being slavery.

In the First Battle of Bull Run (known in the South as First Manassas) on July 21, 1861, 35,000 Confederate soldiers under the command of Thomas Jonathan “Stonewall” Jackson forced a greater number of Union forces (or Federals) to retreat towards Washington, D.C., dashing any hopes of a quick Union victory and leading Lincoln to call for 500,000 more recruits. In fact, both sides’ initial call for troops had to be widened after it became clear that the war would not be a limited or short conflict.

. . .

Toward a Union Victory (1864-65)

In March 1864, Lincoln put Grant in supreme command of the Union armies, replacing Halleck. Leaving William Tecumseh Sherman in control in the West, Grant headed to Washington, where he led the Army of the Potomac towards Lee’s troops in northern Virginia. Despite heavy Union casualties in the Battle of the Wilderness and at Spotsylvania (both May 1864), at Cold Harbor (early June) and the key rail center of Petersburg (June), Grant pursued a strategy of attrition, putting Petersburg under siege for the next nine months.

Sherman outmaneuvered Confederate forces to take Atlanta by September, after which he and some 60,000 Union troops began the famous “March to the Sea,” devastating Georgia on the way to capturing Savannah on December 21. Columbia and Charleston, South Carolina, fell to Sherman’s men by mid-February, and Jefferson Davis belatedly handed over the supreme command to Lee, with the Confederate war effort on its last legs. Sherman pressed on through North Carolina, capturing Fayetteville, Bentonville, Goldsboro and Raleigh by mid-April.

Meanwhile, exhausted by the Union siege of Petersburg and Richmond, Lee’s forces made a last attempt at resistance, attacking and captured the Federal-controlled Fort Stedman on March 25. An immediate counterattack reversed the victory, however, and on the night of April 2-3 Lee’s forces evacuated Richmond. For most of the next week, Grant and Meade pursued the Confederates along the Appomattox River, finally exhausting their possibilities for escape. Grant accepted Lee’s surrender at Appomattox Court House on April 9. On the eve of victory, the Union lost its great leader: The actor and Confederate sympathizer John Wilkes Booth assassinated President Lincoln at Ford’s Theatre in Washington on April 14. Sherman received Johnston’s surrender at Durham Station, North Carolina on April 26, effectively ending the Civil War.