Weegy: What effect did the Wilmot Proviso have on relations between the North and the South? it increased tensions further between the North and the South [ ] User: Why did President Polk support the U.S. acquisition of both Texas and the entire Oregon territory? Weegy: Why did president Polk suppost the u.s. acquistion of both Texas and the entire Oregon territory? ... [ Why did president Polk support the US acquisition of both ... ] User: Why did President Polk support the U.S. acquisition of both Texas and the entire Oregon territory? No links please. Weegy: President Polk supported the U.S. acquisition of both Texas and the entire Oregon territory because he believed in "Manifest Destiny" even more than most did. (More)