the possible need for an amendment to the Constitution to justify theaction. Finally, under intense pressure, he allowed the purchase and setan important precedent. His action established the power of the presidentto expand the borders of the United States under the existing powers of theConstitution. Despite the economic and political implications of the LouisianaPurchase, the Mexican-American War (1846-1848) had more significanthistorical implications on this time period. While disagreements betweenthe two countries had been accumulating for two decades, the war wasprimarily the result of American feelings of "manifest destiny" to expandtheir borders. The treaty of Guadalupe Hidalgo, which ended the war,granted the United States the regions of California, Nevada and Utah, andparts of Arizona, New Mexico, Colorado, and Wyoming. However, thesignificant result of the war on United States' history would be thecontroversy over whether the territories acquired should be slave or free.The country, at this time, was divided between proslave sentiment in theSouth and antislave sentiment in the North. Various attempts at compromiseto settle the controversy, such as "The Compromise of 1850" and the "KansasNebraska Act" failed. Finally, when the issue could not be resolpeacefully, the country was drawn into a civil war. It is evident that theoutcome of the Mexican-American War became one of the most influential,indirect causes of the Civil War. Both the Louisiana Purchase and the Mexican-American War expandedUnited States borders and had beneficial economic impacts. However, theimplications of expansion brought about by the Mexican-American War weremore significant. While the Louisiana Purchase helped define theconstitutional powers of the president, the Mexican-American War furtherexacerbated the slave issue which ultimately resulted in civil war. The Monroe Doctrine was the most important assertion to date of UnitedStates' fo...
