The US tried to expand its territory so much that it even caused a war against the Mexicans in the American-Mexican War. Territorial Expansion Wealth is the primary reason for territorial expansion. States would not fight tooth and nail over territories however small they are if those territories do not bring or do not have the promise of generating profit. The world was virtually unknown and unchartered before the invention of the sail, and even then, new, unclaimed lands were hard to find. Power belonged to the nation with most wealth, and territories translated into profit.
Therefore, the nation with the most land was the most powerful. If wealth meant power, so too did military supremacy, and what better way to gain military advantage over others through established colonies around the globe? In order to dominate the world, one must take a hold of most of it. The United States government realized this, so when opportunities came, the government expanded their territory through treaties and even literally bought territories as if they were real estate today. Acquisition of New Land
The map of the United States today is not the same as it was when it was first established. From the original thirteen states, it grew to an astounding fifty states, more than doubling its size. Some of the new states that were newly acquired with the wealth-driven territorial expansion in mind were Oregon, Florida, and Louisiana. Oregon was a territory rich in fur products, and traders were already settling in the area even before it joined the Union. It finally became an official state of the US on the 14th of February 1859. The territory was basically acquired through natural settlement.
People kept on coming, so they might as well claim the land. The territory at first was shared with the British but was resolved with the Oregon treaty. Florida is another state that was acquired with wealth in mind. Floridas land is suitable for plantations which brings a lot of profit. Florida was a Spanish colony before frequent US campaigns against the Seminole Indians in Florida revealed how vulnerable the area was, so the US army eventually occupied it which led to Spain being forced to sell Florida for $5 million and an agreement that the US will not claim Texas.
The last and biggest expansion so far is the acquisition of Louisiana. Louisiana was a French territory, but when the French reintroduced slavery, anti-slavery factions booted them out. Napoleon then decided just to sell the territory to the US. The French sold Louisiana to the US for $15 million, but the French received only about $8 million because of some discount Napoleon arranged. Mexican-American War
Texas was another territory that was acquired by the US to gain more access to the Pacific Ocean, which would open ports and would be a vital military advantage. Texas was a Mexican territory, but Texas gained independence. Mexico only viewed Texas as a delinquent state, so when the US supported Texas, war was inevitable. The one to blame in this war was the Mexican government because of their refusal to accept Texas independence. If they only accepted that they can no longer keep Texas and respected its independence, the war would not have occurred.