International borders have always been centers of conflict, and 
the U.S.-Mexican border is no exception. With the European colonizing 
the New World, it was a matter of time before the powers collided. The 
Spanish settled what is today Mexico, while the English settled what 
is to day the United States. When the two colonial powers did meet 
what is today the United States’ Southwest, it was not England and 
Spain. Rather the two powers were the United States and Mexico. Both 
Counties had broken off from their mother countries. The conflict that 
erupted between the two countries where a direct result of different 
nation policies. The United States had a policy of westward expansion, 
while Mexico had a policy of self protection. The Americans never had 
a written policy of expansion. What they had was the idea of "Manifest 
Destiny." Manifest Destiny was the belief that the United States had 
the right to expand westward to the Pacific ocean. On the other hand, 
Mexico was a new country wanting to protect itself from outside
powers. Evidence of U.S. expansion is seen with the independence of 
Texas from Mexico. The strongest evidence of U.S. expansion goals is 
with the Mexican-American War. From the beginning, the war was 
conceived as an opportunity for land expansion. Mexico feared the 
United States expansion goals.
      During the 16th century, the Spanish began to settle the region. 
The Spanish had all ready conquered and settled Central Mexico. Now 
they wanted to expand their land holdings north. The first expedition 
into the region, that is today the United States Southwest, was with 
Corando. Corando reported a region rich in resources, soon after 
people started to settle the region. The driving force behind the 
settlement was silver in the region.  The Spanish settled the region 
through three major corridors; central, western and eastern. The first 
settlements were mainly through the central corridor. The Spanish went 
thorough what is now the modern Mexican state of Chihuahua into the 
U.S. state of New Mexico. Eventually the Spanish established the city 
of Santa Fe in 1689. The eastern corridor was through modern day Texas 
and led to the establishment of San Antonio. The eastern expansion was 
caused by the French expansion into modern day Louisiana. The Spanish 
crown wanted a buffer between the French in Louisiana and central
Mexico. The last corridor of expansion was in the west, through the 
sea, which led to the establishment of San Diego in 1769 and Los 
Angles in 1781. 
      The Spanish were not the only European power to colonize the new 
world; French, English and the Dutch also settled North and South 
America. The Spanish and the French settled what is present day 
U.S.-Mexico border region. The French settled modern day U.S. midwest, 
while the Spanish settled present day Mexico and U.S. southwest. As 
time went on, European influence in the region diminished.. The French 
sold there claims to the United States, in 1803 with the Louisiana 
Purchase. Mexico gained independence from Spain in 1821. Once the 
United States bought the Louisiana Purchase, western expansion began. 
This set the stage for major conflict in the region. 
      The United States gained independence from England in 1775. 
After 1775, the Americans started to expand west. By the time Mexico 
gained independence, the United States had reached the Mexican 
frontier. Mexico needed to protect its northern borders. To protect 
the border region, Mexico needed to populate the area. Mexico 
continued the policy started by Spain of allowing Americans to settle 
Texas. The Americans had to follow Mexican law, religion and customs. 
The settlement of Texas played into the United States’ expansion 
plans.
      Eventually Mexico City closed Texas from more Americans from 
entering. This angered the Americans wanting to enter and Americans 
already living in Texas. Texas revolted from Mexico in 1833. Mexicans 
did live in Texas, and fought for the independence of Texas. The 
majority of Texans were Americans and fought for their independence. 
After the war the Americans intentionally or non-intentionally forced 
most Mexicans out of Texas. The ones that stayed faced racial tensions 
that continue to today. 
      After gaining independence from Mexico, Texas wanted to join the 
United States immediately. The U.S. Congress voted against Texas from 
joining the Union. Congress was worried that annexation of Texas would 
anger Mexico. Mexico had never officially recognized Texas as 
independent. Congress was concerned that annexation would start a war 
with Mexico. Mexico’s repose to American annexation was not the only 
factor in deciding against annexation. If Texas was to become a state, 
it would be a slave state. At the time, the United States an even 
balance between slave and non-slave states. Texas entering the Union 
would disrupt the balance, giving slave states an advantage in the 
U.S. House and Senate. Since the United States was not ready to annex 
Texas, Texas declared itself a sovereign country. In 1837 President 
Andrew Jackson formally recognized Texas a country. 
      Texas wanted to be part of the United States. It needed the 
protection of the Untied States. President Tyler could not get the 2/3 
majority needed to admit Texas. Instead, he changed the law to require 
only a simple majority. It was not until 1845 and two Presidents later 
that Texas was annexed into the United States. Mexico protested the 
admission of Texas into the United States. The United States saw 
Mexico’s protest as a excuse to spend troops into Texas.
      The annexation of Texas was a represented the United States 
expansion goals. The United States wanted to settle in Texas, but 
Mexico owned the land. That did not matter to the United States, they 
settled in the region regardless. The Americans that settled the 
region agreed to Mexican law and customs, but still considered 
themselves Americans. After the annexation of Texas, Texas also wanted 
to expand. Texas claimed that New Mexico and California were part of 
Texas. The boundary with Mexico was also disputed. The United States 
claimed that the Texas border was at the Rio Grande. Mexico disagreed, 
Mexico stated the border was at Nueces River. The United States did 
try to settle matters diplomatically. The United States sent 
inexperienced diplomat John Slidell. Slidell tried to buy area known 
as the U.S. Southwest. Slidell, being an inexperienced diplomat, was 
rejected. Not only was he not successful in buying the land, he 
aroused Mexican fears. This set the stage for the Mexican-American 
War.
      The United States also had no written policy of expansion, but 
the government quietly supported it. The United States has always had 
troops the region, even though they held no land in the region The 
United States kept ships off the coast of California. In 1842 the U.S. 
commander in the region, Commodore Thomas Jones, attacked and took the 
city of Monterrey in California. He falsely believed that Texas and 
Mexico were at war. Once he realized his mistake he withdrew his 
forces and apologized to the Mexican government for his action and 
claimed that he did not act with orders from the U.S. government. 
Although Jones claimed that he did not act with orders from the U.S.
government, clearly the government did not stop the practice. Another
example of the United State’s expansion goals was the Mexican-American 
War.
      This is the first time America has fought a war with land 
expansion as its main goal. The war started on April 25 1846 with the 
attack from Mexican troops and the counter attack from General Taylor 
of the U.S. Army. Taylor sent a message to President Polk that 
hostilities have started. President Polk, with a pre-drafted 
declaration of war, asked Congress to declare war against Mexico. 
President Polk knew that Mexico would lose the war and would gain new 
lands in the end. 
      The Mexican-American war lasted two years, and ended with the 
signing of the Treaty of Guadeloupe on February 2 1848. The United 
States had succeeded in winning the war. With the Treaty of Guadeloupe 
the United States had succeeded in completing its Manifest Destiny. 
The Treaty itself represented the United States expansion goals. The 
United States wanted to settle on were the international border was to 
be. Mexico wanted the border to north of the Rio Grande river, but 
finally decided upon the middle of the Rio Grande river. Mexico having 
been bankrupt from the war, agreed to take the 15 million as payment 
for the vast land. In addition, the United States agreed to pay off 
all Mexican debts owed to the United States. This amount was small in 
comparison to what the United States gained in territory. The United 
States took advantage of a weak country of obtained its expansion
goals.
      Another example of the United States taking advantage of Mexico 
is the Gasden Purchase. The Gasden Purchase was ratified in 1854 for 
the selling price of 10 million. Mexico was going through rough 
economical time and desperately needed the money. The United States 
seeing an opportunity to build a railroad through the region brought 
the land at a cheap price. The selling of the Gasden Purchase was the 
down fall of President Santa Ana, and led to his replacement.
The conflicts along the border region were a direct result of U.S. 
expansion policies and Mexican fear for the United States. The 
Americans saw Manifest Destiny, westward expansion, as there God given 
right. The United States proved often that it supported policy of 
expansion. With the Mexican-American war, the United States completed 
it's Manifest Destiny. The United States completed Manifest Destiny at 
the cost of the Mexican government and its people.