Final answer:
The dramatic increase in westward migration in the 1760s was fueled by population growth, land hunger, political pressures, and economic motivations.
Step-by-step explanation:
The dramatic increase in westward migration in the 1760s was fueled by a variety of factors. One factor was the population growth of the United States, which increased from about five million to over twenty million in the period from 1800-1850. Americans were increasingly land-hungry, and the declining soil fertility of overworked farms in the east made the cheap land of the west more attractive.
Another factor was the political pressure to occupy the West before other powers, such as the British, could do so. Westward expansion was seen as a way to counterbalance the industrialized northeast and maintain the ideals and values of Jefferson's yeoman farmer. The expansion also had economic motivations, with merchants wanting control of west coast ports for trade with Asia.
In summary, the dramatic increase in westward migration in the 1760s was driven by population growth, land hunger, political pressures, and economic motivations.