Explain how the civilizations of the aztecs, mayans and the incas altered their environments to create an increase in food production

The Aztecs, Mayans, and the Incas were all great civilizations that had their economies and prosper based around the agriculture and the advancements in that field.

All three civilizations used sophisticated methods of irrigation for their time. While the Aztecs and the Mayans were building channels in lowlands that had a constant flow of water, the Incas were building stream like irrigation ditches on the slopes of the mountains that were well controlled.

Also, the Aztecs and the Mayans were building water collectors, so that they have water for the drought periods, while the Incas were using the method of terracing in order to produce food in places in which would be impossible otherwise.

The irrigation methods, the collection of water, and the terracing, were all methods that were enabling a very productive farming, which resulted in high production of food, which in turn was able to sustain very large populations of people.

yellow fever and other tropical diseases

b) the confederacy had to pay all union war expenses.