What happened during and how did each of the following impact expansion and the map of the United States?

1. Texas annexation
2. The Mexican American war
3. Mexican cession
4. The Gadsden purchase

if this is 30 points how come is this 15 it say but anyways yeah I need this one also any body got a thought of what it could be

i do believe its (d) it allowed the government to offer pioneers sixty acres of western land if they lived on it and made improvements to it.

explanation: signed into law in may 1862, the homestead act opened up settlement in the western united states, allowing any american, including freed slaves, to put in a claim for up to 160 free acres of federal land. by the end of the civil war, 15,000 homestead claims had been established, and more followed in the postwar years

it was douglas macarthur..