Manifest destiny was realized in the mid-1800s in various ways. with the oregon territory, it was through negotiation. with the southwest, it came from war with mexico and taking the land. in your opinion, would such large territorial expansion be possible today for the united states? why or why not?

yes, America could still in fact get a large territory. They could get it by force (war), Buy the land, or a treaty. The bigger question however, is it worth doing it. If America wants to get the land by war that just adds to what the're doing in the middle east, and if it's a neighbor next to them (Canada or Mexico) the blood shead could be high because of pupulated cities. As for money or a treaty it wouln't be that much of a risk but it depends on how much money and the details of the treaty.

map scale refers to the relationship (or ratio) between distance on a map and the corresponding distance on the ground. for example, on a 1: 100000 scale map, 1cm on the map equals 1km on the ground.