The principal goal of the supporters of manifest destiny in the 1840s was to

 expand the country Westward.

Explanation:  Both government and individual felt nothing should stop the all-powerful drive to expand the size of the country.

populist movement, in u.s. history, politically oriented coalition of agrarian reformers in the middle west and south that advocated a wide range of economic and political legislation in the late 19th century. thus in 1892 their leaders organized the populist, or people's, party, and the farmers' alliances melted away.

i would have to say i believe that it is a.