1. why did thomas jefferson believe that the united states needed to acquire the louisiana territory? 1) he believed that the united states needed the territory as a place to relocate native americans. 2)he believed that acquiring the territory was necessary for the safety of the united states from european colonial powers. 3)he believed that owning property, especially farm ownership, was an important part of freedom. 4)he believed in the manifest destiny of the united states. 8. which factors encouraged plantation development in the south? (3 points) 1)the southern climate encouraged investment in agriculture. 2)the development of the cotton gin and northern industrialization led to a significant demand for cotton. 3)a decrease in tobacco production and an increase in more labor-intensive wheat and rice production. 4)higher prices meant that plantations earned higher profits.