It may be a bit of an exaggeration to say that the the the North could have defeated the South "with one hand tied behind its back," as Foote does. It's also difficult to say with any degree of certainty how chance and individual human agency may have affected the course of any particular set of events in one way or the other, or to say definitively that the South had no chance of winning the war. But it is basically right: there is a consensus among historians that the North held significant advantages that heavily weighted the outcome of the Civil War in its favor. As I'm sure the Ken Burns documentary talks about (although its been a while since I've seen), the industrial and urbanized North was the location of the majority of capital and industry in the U.S. at the time, so it had the superior means of financing and equipping armies. It had more population overall and a better ability than the South to replace the numbers of men it had lost. In addition, it had a greater network of roads and more miles of railroads, which enabled more efficient movement of goods and people across the nation. The South on the other hand was considerably less urbanized and industrialized and had a much smaller population and a less extensive transportation system. In raw resources alone, the North had the clear advantage, and in shaping the capabilities and playing field of each of the belligerents, those set of resources had a significant role to play in determining the outcome. The South for much of the war was clinging on as much as it could, fighting a battle that over time began to grow closer and closer to home, and hoping (and failing) to string enough victories together so that it could garner international recognition and possibly foreign military support. The North's problem, for the most part, was an issue of effectively mobilizing resources to fight the war. It suffered from a sense of overconfidence (as the First Battle of Bull Run demonstrated) and poor leadership and military decision-making (see General McClellan) which prevented it from landing a decisive victory early on.

In general, I would avoid the fallacy of determinism in thinking that this MUST have been the only way that events could have taken place. The South was clearly an underdog the entirety of the war, but there were possible (if unlikely) ways for it to win. Looking at the entire balance sheet of the war, however, the South definitely had the deck stacked against it.