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After the successful War of Independence against the United Kingdom, the United States established its border with New Spain and what would become the Louisiana Purchase, a territory stretching mostly west of the Mississippi River. The Treaty of Fontainebleau in 1762 ceded what would become the Louisiana Purchase to Spain from France. However, in 1800 France regained the territory from Spain. Napoleon, although wanting to keep the territory to create an empire in North America, could not afford to hold the territory while fighting the United Kingdom and other states. His need for money led prompted the French to sell the territory to the United States in 1802. This effectively created the border with New Spain, what was then Mexico under Spanish rule, along what are now Texas, Oklahoma, Colorado, Wyoming, and Montana. This border stayed relatively stable for the next few decades.  From 1810-1821, Mexico fought its own war of independence with Spain. Mexico succeeded in 1821 in establishing itself as an independent country that controlled what is mostly the Western United States and modern Mexico. The first few decades of Mexico's history were turbulent, as a struggle for power between conservatives, who wanted a centralized form of government, and liberals, who wanted a more federal system with more freedom for the states of Mexico. One early goal for Mexico was to stabilize its frontier regions, particularly in what is now Texas. Mexico invited settlers to come to the region that was underpopulated, allowing settlers from the United States to arrive. Very soon, these settlers outnumbered Mexicans and native populations living in Texas.