in the 1840s, the united states had a dispute over the oregon country with; which helped prevent a war between the united states and spain?; in 1845, the united states annexed the republic of florida. california. texas. oregon.; in the mid-1800s, one result of manifest destiny was that; how did john quincy adams negotiate the adams-onรญs treaty?; as a result of the adams-onรญs treaty the united states gained which territory from spain; as the united states expanded in the 1800s, the north and south disagreed about whether; the belief that the united states had a mission to expand westward was called