That, and the fact that North's industrial capacity, population, and rail capacity absolutely dwarfed the South's.
Can you imagine being a Northerner at the start of the civil war. All the fancy lad West Point military guys are Southerners. Your president is a backwoods yokel one term congressman and your generals are some guys we found at a 7-Eleven. It's over for our ass...unless all those guys are geniuses