US Victory in the Mexican-American War

Manifest Destiny and America’s Military Success, 1846-1848

Oct 18, 2008

Due to the belief in the validity of Manifest Destiny, especially in military and political arenas, the United States' military had enough backing to win against Mexico.

A combination of political and military influences can account for the success of American forces in the Mexican-American War. America was operating under the influence of the concept of Manifest Destiny. Manifest Destiny’s greatest proponent, according to Richard Frank in a lecture to Norwich University’s Military History program, was President James Polk.

Manifest Destiny and President James Polk

Polk’s belief in Manifest Destiny allowed him to prepare America for war by informing American military commanders as to the specific military goals of the nation should a war with Mexico begin. Kenneth J. Hagan, in his work This People’s Navy,states that hrough Manifest Destiny, and a coordinated, driven effort on the part of the military, Polk hoped to create an American empire. In The American Way of War historian Russell F. Weigley also shows that PresidentPolk was backed by fellow expansionists who wished to see the territorial growth of America. Political backing and pre-war planning then, allowed Polk to use the conflict with Mexico over the borders of the recently annexed territory of Texas as a premise for war.

War with Mexico

Once hostilities with Mexico began in earnest, Polk used three key commanders to obtain victory. These commanders were Generals Winfield Scott and Zachary Taylor, and Commodore Matthew C. Perry. Both Perry and Taylor brought with them aggressive determination and decisiveness. Scott’s talent was a genius for strategy and tactics. With these three men commanding the American forces Polk sought to expand the borders of America. In regards to the Army itself Polk – according to Allan R. Millett and Peter Maslowski in For the Common Defense -- convinced the government to double the size of the standing army as well as to call for 50,000 militiamen.

With the increased troop strength combined with the traits of each of the commanders, America was able to achieve victory. This was brought on by a change in what had been traditional American strategy and tactics.

New Strategies and Tactics for the American Military

Hagan shows that the United States Navy no longer sought to fight a defensive war or to interrupt commerce through the use of privateers. Instead the navy employed offensive tactics consisting of blockades, bombardments, and amphibious assaults. Commodore Perry himself, as recorded by Hagan, led amphibious assaults when no fighting could be found on the water.

Taylor, like Perry, was an aggressive commander. Millett and Maslowski relate how General Taylor was cool under fire and capable, an inspiration to troops who might otherwise break in desperate circumstances. General Scott, though, was the lynchpin of the three. He was, according to Frank, a strategist who planned for all contingencies. He understood the political goals of the United States and sought out the surest way to achieve them. Scott knew that the destruction of the Mexican state was not necessary to achieve America’s war aims. Seizure of the Mexican capital would suffice. Thus Scott, Weigley states, avoided battles which would be costly for American troops, and for Mexican troops as well. Scott strategy then, according to Weigley, sought to make the position of the Mexican government untenable with American forces occupying the City of Mexico.

A sound military strategy consisting of offensive tactics, well defined goals, aggressive commanders, and increased troops combined to form the military’s share for American success in the Mexican-American War. Polk’s desire to fulfill Manifest Destiny, his excellent communication of America’s strategic goals to his commanders, prewar planning, and the government’s approval of increased troops formed the political aspect of America’s Mexican-American War equation. Thus the political and military structures of America joined for the positive and successful accomplishments of American forces in the Mexican-American War.

Sources

Millett, Allan R. and Peter Maslowski. For the Common Defense. New York, NY: The Free Press, 1994.

Weigley, Russell F. The American Way of War. Bloomington, IN: Indian University Press, 1997.

The copyright of the article US Victory in the Mexican-American War in Military History is owned by Nicholas Efstathiou. Permission to republish US Victory in the Mexican-American War in print or online must be granted by the author in writing.