Some how or another, a lot of folks have come to believe that victory or defeat of the Confederacy rested solely on General Lee and his Army of Northern Virginia. This is not the case. The war was fought over thousand of square miles and in most Southern states by thousands of soldiers not in the Army of the Potomac or the Army of Northern Virginia. Someone once stated the Lee’s defense of Northern Virginia was akin to saving the front porch, while the rest of the housed burned down. That may well be a very accurate appraisal of events.
Of course what you say is true, and the resources available to the North far outweighed those the South had available to them. The fact that they were able to extend the war as long as they did is a testament to their abilities even with those limited resources.
The war was lost before the first shot was even fired. The only possible way of the rebels winning was if a foreign nation recognized and assisted them, specifically Britain. However, the slavocracy badly overestimated the power of cotton, and underestimated Britain’s anti-slavery sentiments.
With slavery so openly and brazenly enshrined in the confederate constitution there wasn’t a snow balls chance in hell of Britain siding with them. And none of the other great nations at the time would do anything counter to England.