Why had the North and the South grown so far apart by 1861?

The North wanted to end all immigration to keep wages high and keep many things running in their areas, but the South needed more factory workers and etc, this is all due to slavery in the South, and because slavery had stopped so they needed more workers to run thing for them.

the answer is

montesquieu took the view that the roman republic had powers separated so that no one could usurp complete power. in the british constitutional system, montesquieu discerned a separation of powers among the monarch, parliament, and the courts of law.