How did the Union military seek to defeat the South's advantage of interior lines?

Answer 1

In the early stages of the US Civil War, the Union's generals and President Lincoln were astonished that the South's ability to use its interior lines to shift troops, often by railway, to areas where they were most needed. This is why, for example, the First Battle of Bull Run was a Southern victory. Via railroad, General Johnston's forces used the railroads to move to the Bull Run battle scene and reinforce General Beauregard's army. In order to offset this advantage the Union adopted a strategy of simultaneous advances into the South and thereby hampering the Rebel's defense by the use of its interior lines.