A explosion, which is unknown even to today what caused it to blow up.... but the US blamed it on the Spanish and declared war on Spain
hope this helps
Answer:
The terraces were built to make the most efficient use of shallow soil and to enable irrigation of crops by allowing runoff to occur through the outlet. The Inca built on these, developing a system of canals, aqueducts, and Iquitos to direct water through dry land and increase fertility levels and growth.
Explanation:
Henry Clay, William H. Crawford, John Quincy Adams, and Andrew Jackson
They needed population and mexicans wouldn't move there in the numbers they needed