<span>Many Americans began to support imperialism in the late nineteenth century for anumber of reasons. Let us look at a few of them. Many believed that the United States needed new markets for its manufactured goods. ... So many leaders advocated expanding American influence around the world through imperialism.</span><span>hope it helps
The Jay's Treaty, Monroe Doctrine, and Adams-Onis Treaty forced the British to leave the Eastern US (and pretty much all of the America's) and they 'forced' Spain out of Florida.
