Final answer:
American mythologies portray the United States as the land of opportunity and freedom to create a sense of national identity and cohesion.
Step-by-step explanation:
The characteristics of American mythologies include the portrayal of the United States as the land of opportunity and freedom, while disregarding the negative aspects of its history. These mythologies also often emphasize a grand and splendid history, distinct from all others. The purpose of these mythologies is to create a sense of national identity and cohesion among the American people.