Where was the Civil War fought?

The Civil War was mostly (except for some naval engagements) fought in the continental United States, in what military historians divide into two "theaters" of war. The first, in the east, consisted primarily of the Union's attempt to capture the Confederate capital at Richmond, Virginia. For this reason, a disproportionate amount of battles were fought between Washington, D.C. and Richmond, along what is today the I-95 corridor. Two Confederate invasions of the North resulted in the battles of Antietam and Gettysburg, and fighting also took place in the Shendandoah as well as the James River peninsula in 1862. 

The western theater consisted first of Union attempts to control the major river complexes before cutting off Confederate control of the Mississippi. After this effort was completed at the siege of Vicksburg, Mississippi, the theater shifted to Georgia, and later through the Carolinas with General William Sherman's march. The war was also fought along the coast of the South, as the Union tightened its grip on the Confederacy by taking one port town after another, most of which were heavily fortified.