They have a good influence on it and they are always there for any need that might come up
I would say that based on this excerpt and your knowledge of American history, the stock market crash made Americans lose confidence in business because B. people worked diligently to participate in the building of the American dream with the understanding they would profit.
However, when the stock market crash happened, they lost all faith and confidence.
The word you're looking for is prowess, however you didn't post a list. Prowess means superior skill, strength, or ability. Other similar words are expertise, aptitude, and mastery.
