In the 1840’s, president james k polk’s belief in manifest destiny led to

The establishment of new colonies in the Caribbean.

Explanation:

Manifest Destiny was an idea, popular during the 1800s, that stated that it was the destiny of the United States to expand as much as possible, and take over the continent. Proponents of such a view believed that the United States was blessed and chosen, due to some characteristics, such as its democratic rule. This led many people to support imperialist projects, such as that of establishing new colonies in the Caribbean.

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.