America developed flying artillery to help in battles.
Texas, California, Colorado, Arizona, Wyoming, and New Mexico were all parts of Mexico until the treaty of Guandalupe Hidalgo (Except AZ and NM).
The Gadsden Purchase claimed Arizona and New Mexico.
In Mexico, the war is taught as "The United States' Invasion of Mexico."
Both Mexican officers and politicians were not effective.
The Battle of Chapultepec is the most famous battle because of six Mexican kids who died fighting invaders in the academy they refused to leave (They are called "Ninos Heroes" or hero children).
Some American soldiers joined Mexico's side during the war.