In this situation, the externalities that arise from studying is the unability to enter college and obtain good-paying jobs.
From the description above, we can conclude that Jacob is much more likely to experience these externalities since he does not consider the importance of studying and how it might influence his future.
Answer:
Lincoln's election was seen as the last straw to the Southerners about their place in the union. This led to the process of secession a short time later, also leading to the eventual Civil War.
It is basically saying that the main part of the whole story is over. All their skills have been put to good use, because they completed the task that they trained for, and the stress that was with them before the battle is now gone. But does not mean the entire quest is over yet, just the most difficult part.