Some historians argue that calling the Civil War North the Union concedes too much
For generations, Americans have spoken of the Union versus the Confederacy. In 2015 historian Michael Landis argued the phrasing quietly accepts the secessionist view that the country had broken apart, when the United States never ceased to exist. By 2021 the Army University Press was swapping the word for Federal Government.
In Civil War usage, the Union meant the federal government and the states that stayed loyal after Southern slave states seceded following Abraham Lincoln's 1860 election. His administration insisted the national government and its constitution were permanent and refused to recognise the Confederacy. The loyal side is often called the North, though four slaveholding border states and the new state of West Virginia remained with it, and many Black Southerners, free and enslaved, backed its war effort.
The word had deep roots. The first governing document was the Articles of Confederation and Perpetual Union, and the 1787 Constitution speaks of forming a more perfect Union in the name of the people rather than the states. Preserving the Union was a familiar phrase long before fighting started.
Material advantages were overwhelming. The loyal states were more industrial and urban, had stronger transport and finance, and began with a five-to-two edge in manpower. The Northeast and Midwest supplied munitions, food, horses, money and most of the soldiers. Fighting took place almost entirely in Confederate territory, so the loyal states largely prospered, helped by heavy federal spending and a brand-new national banking system. Much of that strength, though, went into garrisoning captured regions and guarding railways, and full mobilisation took time.
Politics never paused. The attack on Fort Sumter briefly produced near-unanimous Northern resolve, but by 1862 Democrats had divided into War Democrats and anti-war Copperheads, and made big gains that year while warning of centralised power and profiteering. Lincoln, widely praised by historians for political skill, learned strategy and diplomacy on the job and clashed with Radical Republicans in Congress over military matters. Congress meanwhile passed laws that reshaped the country for decades, among them the National Banking Act, the Homestead Act and the law that launched the Pacific railroad.
Source: Union (American Civil War)