its not onomatopoeia or repetition and imagery is making a picture in your mind so its personification because its saying the prairie is drawing them close but a prairie cant actually draw.
the exact definition of natural vegetation is a cover of plants that can grow alone with little to no human interference, so i believe this fits your description best!
Answer: She was reluctant to define anything remotely resembling a national character because " it was a mongrel nation." There were so many different ethnic groups that had merged into one. This made it difficult and sometimes pointless to make just one group "entirely American."