Conclusion

The United States and Mexico could not agree on the border

between them.The United States claimed that Mexican

soldiers crossed over to attack some American soldiers. Some

in the United States said it was just an excuse to get land

claimed by Mexico. Others feared that the practice of slavery

would spread to new land gained by war.

Most of Congress as well as President Polk were for the

war.They believed in Manifest Destiny, and Polk wanted

California. In May 1846, the United States declared war.

It became known as the Mexican–American War.

News of the war took more than a month to reach

California. On July 2, Commodore John D. Sloat, a

commander of U.S. Navy ships in the Pacific, waited for

news. He had orders to take California ports when war

broke out. He decided to take action on July 7, and raised

the American flag over Monterey.Yerba Buena and San

Francisco Bay were captured, and Commodore Robert

Stockton took San Diego and Los Angeles. Thus the

Success of the Americans Caused for the Mexicans to

eventually surrender and sign a treaty.