“The Changing Perspectives and Tensions of 19th Century America: Civil War, Native American Responses, and Northern-Southern Tensions”

Please be sure to provide responses for two of the three selections. Be sure to include and cite specific examples from the assigned materials (lectures, https://www.americanyawp.com/ to an external site, and the documentaries linked in our course schedule). 
1. How and why did the meaning of the Civil War evolve between 1861 and 1865?
2. How did Native Americans respond to western expansion in the first forty years (c.1800-1840) of the nineteenth century?
3. How and why did tensions between the northern and southern United States heighten between 1846 and 1854?