Why was keeping the border states loyalty so important to the Union war effort?

Answer 1

The confederacy wanted the loyalty of the border states so that they would be slave states, increasing the power and strength of the south. Also, it would give the south an advantage against the north because there would have all the resources like grain and wheat that the border states grow.

Answer 2

Because their loyalties would have made a crucial difference to the battlefield situation.

If Kentucky, Missouri, Maryland and Delaware had gone Confederate, Washington would have been surrounded by enemy states, and the Union cause would probably have been lost.

Answer 3

Three of the four so-called "border states" which were Missouri, Kentucky and Maryland were vital for the Union's war effort to end the Confederate rebellion. Delaware was a slave state, however, it had on about 900 slaves, and it did not really figure into anyone's calculations. It was not even tempted into joining the Confederacy. Now the remaining border states were also slave states. Their importance to the South and the North cannot be underestimated. These states were well populated and had Natural Resources both in farm crops and a good degree of manufacturing. If these states had joined the Confederacy, it would have immensely helped the South and would dramatically harm the North. A worse case scenario would have been Maryland. It had strong Southern sympathies and Maryland and Virginia would have surrounded Washington DC., forcing a relocation of the North's capital.

Missouri could also have been a problem as well, It;s major city was St. Louis and it sat right on the Mississippi River. Having Missouri join the Confederacy would have changed the entire complexion of the war. Kentucky was important too, but Missouri and Maryland could have changed everything.