How did American application of warfare change from the War with Mexico to the Civil War, history homework help

1. How did American application of warfare change from the War with Mexico to the Civil War?

2. Who were American soldiers in the Civil War and why did they fight?

– Minimum of 200 words per question using this book:

Millett, A. R., Maslowski, P., & Feis, W. B. (2012). For the Common Defense: A Military History of the United States from 1607 to 2012. New York, NY: Free Press.

– For each answer can use outside source but should be kept to a minimum

– Information found in chapters 6 & 7 Pages 142-217