Complete the paragraph about the reason for westward expansion in the united states during the nineteenth century. the us government supported westward expansion. it envisioned a nation that covered a vast expanse of land from the east coast to the ocean. the acquisition of texas, the oregon territory, and the between 1845 and 1853 make this vision a reality. most of this expansion happened during the presidential term of 1st blank a. indian b. pacific c. atlantic 2nd blank a. east b. southwest c. northwest 3rd blank a. sam houston b. james polk c. stephan austin