The North was always richer than the South...
They also destroyed a lot of the built up wealth in the South.
The South was systematically and intentionally backward.
- Railroads in the South did not cross state lines - by state government edict.
- There was one telegraph line in the South, at a time when the map of telegraph lines in the North looked like a spider web. Again, state law.
- For every factory worker in the South, there was a factory in the North.
Always, after the 1850s. Millard Fillmore (July 9, 1850—March 4, 1853). . Franklin Pierce (March 4, 1853—March 4, 1857) James Buchanan (March 4, 1857—March 4, 1861).All the presidents of the 1850s get, and to an extent deserve, a bad rap. But the net effect of their administrations was to keep the union intact throughout the decade. If the Civil War had started a decade earlier, the correlation of economic forces would have been quite different - and secession might very well have succeeded.