It would be between increased population, a steady stream of agricultural production, and technological advancements. As for the most important one of those three; that would be agricultural production.
They were afraid of what might happen if the Union were to dissolve
At the end of the French and Indian War the British government signed treaties with the Indians in the Ohio territory to restrict the American colonists from moving into there land. The American colonists ignored this British treaty, and started settling in the Ohio, Kentucky, and Tennessee areas. The British government, unlike the American government in the following century (which very seldom honored the treaties they signed with the Western tribes), tried to honor their treaties with he Indians and keep the Americans out. This brought the Americans and British into confrontation and was one of the main factors that led to the Revolution.
