In the spring of 1861, decades of rumble tensions between the northern and southern United States over issues counting states' rights versus federal influence, westward increase and slavery exploded into the American Civil War (1861-65).
The voting of the anti-slavery Republican Abraham Lincoln as president in 1860 reason seven southern states to separate from the Union to form the associate States of America; four more joined them after the first shots of the Civil War were fired.
In the mid-19th century, while the United States understood an era of tremendous growth, an elementary financial difference existed between the country's northern and southern regions. While in the North, industrialized and industry was well recognized, and farming was mostly limited to small-scale farms, the South's wealth was based on a system of large-scale undeveloped that depended on the labor of black slaves to grow certain harvest, particularly cotton and tobacco.
Though on the surface the Civil War may have seemed a irregular conflict, with the 23 states of the Union enjoying an huge advantage in population, developed (including arms production) and railroad construction, the partner had a strong military tradition, along with some of the best soldiers and leader in the nation.
In the First combat of Bull Run (known in the South as First Manassas) on July 21, 1861, 35,000 partner soldiers under the authority of Thomas Jonathan "Stonewall" Jackson forced a superior number of Union forces (or Federals) to run away towards Washington, D.C., dashing any hopes of a quick Union victory and leading Lincoln to call for 500,000 more workers.