Answer:
To provide more farm land for its growing population
Step-by-step explanation:
The first half of the nineteenth century in US history was marked by the conquest of territories. The population, at that time, went from 3,900,000 in 1790 to 7,200,000 in 1810, forming an essentially agrarian society, formed by farms in the Northeast and large exporting farms in the Southeast. Because of this growing population, Yhomas Jefferson wanted the United States to expand, because it would be possible to provide more farmland for the people.