According to a different source, this is the image that the question refers to.
In this question, we are asked to approach the question of "How justifiable was U.S. expansion in the 1800s?" from the perspective of four elements in the painting. This is an example that can help you guide your work:
The angel: "I carry the telegraph, I carry knowledge, I carry progress. You should be grateful."
The cows: "More expansion means more land, which means more farms and more cows. I think I like that!"
The Native Americans: "Quick! Let's get away before this so-called "progress" reaches us! They will continue to expand and take our land even if they have no right to do so."
The passengers in the train: "Without progress, we would not be in this train. I'm so glad we are expanding! It is necessary if we want technology to keep developing."
Although expansion was supported by a large portion of the population of the United States, not everyone believed that this was a good idea. In fact, the Native Americans, as well as many politicians, believed that expansion was not legitimate, and that it could bring more problems than anticipated.