Presidents Thomas Jefferson and James K. Polk both strengthened the United States as a result of their expansionist foreign policies. Jefferson's foreign policy reflected his feelings for France and resulted in the Louisiana Purchase in 1803. Throughout the 1840's, Polk pushed for the annexation of Texas, the Treaty of Guadalupe Hidalgo and the establishment of the Oregon Territory. While not of all of these policies and treaties had immediate effects, almost of all of them had a long term effect on the United States. These expansionist policies and actions by Thomas Jefferson and James K. Polk strengthened the United States economically and in regard to domestic and foreign issues.
The expansion of the United States made the nation much stronger economically. The Louisiana Purchase, negotiated by Jefferson, opened up many new economic opportunities for the United States. New Orleans was part of the territory, and as a result the Mississippi River was opened up for trade indefinitely. This alleviated fears that New Orleans would be closed for Americans and thus blocking the Mississippi River from the ocean. The Treaty of Guadalupe Hidalgo negotiated by Polk greatly improved economic conditions of the United States by making California part of the US. Gold was found in California in 1848 and more importantly, it was found after the Treaty of Guadalupe Hidalgo was completed. If the treaty had not existed, then the gold would belong to Mexico. The push for the annexation of Texas by Polk is also very important to the strengthening the economy of the United States. .
Today Texas is the 3rd highest state in terms of the gross state product contributing $764 billion. Had Texas remained an independent country and not been annexed, this sum of money would not be contributing to the economy of the United States. Economically, these expansions of the United States provided new economic opportunities as well as setting up opportunities for future economic success.