In the years preceding the U.S.-Mexican War, the United States and Mexico were two nations headed in opposite directions.
The United States, fueled by new technological breakthroughs and inspired by the concept of "Manifest Destiny," confidently expanded its territories westward. The young country was regarded as a "go-ahead" nation, looking forward to a future of seemingly endless possibilities for itself and its people. Meanwhile, Mexico struggled to maintain control over the vast expanses of land it had inherited from Spain following its long war for independence. Lacking the resources to settle much of its territory and suffering from deep internal political divisions, Mexico looked to the past for its sense of meaning, back to a time when "New Spain" had once promised to be the continental power of the New World.