This just wasn't true, although it was somewhat more true of the South than the North. Yes units were raised in the various states, and often officered by men from the those states. But in the Union army at least, they were completely integrated. Supply, chain of command, everything. Except at first perhaps, since at that point the units were indeed state militia units, and the Union Army was just not prepared to properly integrate them.
Much the same was true in the South, although it lasted longer, and logistics wise, the Confederate Army never did get completely integrated.
Not being prepared for any war, let alone the next one, is an old American tradition, not fully broken until about 1990, and it will return, probably sooner rather than later. It's demise started with having no choice but to be prepared, at least for the SIOP war. (AKA Globabl Thermonuclear War..toe to toe with the Ruskis)
I looked into this more and you are definately correct that the federal army was very integrated at the start. Thank you.
However, the federal army when the war starts is only 16,000 strong. Distributed mostly throughout the western territories, along the Canadian border and near the Potomic. In a few years this grows into nearly 4 million men and boys having served on both sides combined. That's a 250 times increase in size!
What I was trying to get at was that most military units that fought were regionally (State) provided. And those who fought side-by-side were mostly all from the same state or sub region in a state or near a major river artery. This is nothing like todays military, where any random selection of 10 soldiers from a given unit is highly likely to consist of men from 9 or more States. A military this integrated just couldn't break down into a North and South and go at it today. Nor could we grow it 250 times in size to fight ourselves.
Chain of command would have to be integrated because you couldn't politically have a single state dominate all positions. Plus, we all know Lee was offered the Union Army, but went Confederate because he stayed with his home state. As did most West Pointers. Thus, the leadership of both armies were integrated before the war and then spilt and formed 2 chains of command. If Lee did accept Lincoln's offer, I suspect the war would have been a lot shorter than the 5 or 6 years it went; and a lot less bloody. McCellan was a runner, not a fighter. Integrated leadership goes without saying.
I know slightly more about civil war logistics than David Letterman. Are you certain this function was very integrated, or did each individual army and militia have to provide for their own? I suspect alot of it was the later, especially on the South side. I suspect the logistics people were merged as the armies grew in size and were grouped together. Although I don't know for certain.
I had friends who do Civil War reenactments and I recall them telling me that the individuals soldiers of the era had to provide all their own clothing, boots and initial supplies. Don't recall on who provided the guns, probably a mix. They started Confederate, so the clothing issue may be specific to the South. All I know is that wearing wool, which they did, is quite itchy.