I think the French surrender of Montreal was most significant for Britain as for future America it was, the Battle of Monongahela River when Washington had his first experience with true battle and lost his mentor Braddock.
Banks loaned money to rich tycoons who were expanding the railroads
By the United States in March 4, 1789
The answer to this should be: A sizable middle class has developed.
With a middle class they can create a better governance; The Middle Class has a strong interest in promoting foresighted policies and making government work well because their economic fate is more closely tied to the quality of government than that of the wealthy.
Hope this helped :)
Have a great day