<span>Prior to the Mexican American war president Polk sent John Slidell to Mexico to negotiate an agreement between that the Rio Grande River would be the southern border of Texas. ... The United States annexed the territory of California in 1848 following its victory in the Mexican-American War.</span>
The two american empires were the Incas and Aztecs. They carried Gold and Silver.
Answer:
It was called Rocky Mountain Spotted Fever.
Explanation: I hope I have helped you.