Answer: Scott proposed to defeat the Confederacy largely through blockade of ports and control of rivers leading to the economic 'strangulation' of the Confederacy, which he hoped would prevent a large number of bloody land battles. The Battle of Shiloh preserved an important Union flank along the Mississippi River and opened the way to split the Confederacy along the river. In May and June of 1863 Union General Ulysses S. Grant marched on Vicksburg, Mississippi, and trapped a Southern army led by General John Pemberton.
So, the reason I think this happened is because he wanted to defeat the Confederacy largely through blockade of ports, and control of rivers leading to the economic 'strangulation' of the Confederacy. Strangulation means that someone or something is being strangled... (If you didn't know..)
Hope this helps stay safe and have a great weekend!! :D