He wanted to improve the Nations relationships. hope this helps
At first the Native American's were fine to share their land with the colonist, but it be came more clear that the colonist were starting to push the Native Americans out of their land. So how do the Native Americans think about Manifest Destiny they see it as invasive and intrusive movement that was being done by the colonist and were more than willing to go to war for their land.
The impact of technology in our daily life are different from the impact of the early 1800s in the 1800s people didn't have stuff like smartphones and computers to help with stuff like we do today but back then they had stuff like the telegraph, the telegram, and all sorts of other pieces of technology from back in the 1800s.
Westerners were able to have loan forgiveness to purchase land
During WWII, women went to work in factories while the men were away from war, this actually helped the unemployment rate drop since women were actually being used for something other then just being a "house wife", which was common in that time. Since we were just coming out of the great depression, it was hard for America to have the money to actually make weapons and have a war that we could actually fight.