The key cause was economic hardship
The answer the question is Pennsylvania had the first oil rush in 1859
I don't think that your past should be affected by your future. This is because your past start by pointing out that your ability to envision the future is influenced by your memory from the past. This is because, you tend to use memories of past experiences to predict what your life will be like in the future. It is easier to use your memories when the future you are predicting is very close in time.
