Final answer:
The main driving forces behind U.S. imperialism during the early 1900s included economic motives, political ambitions, and cultural influences, which led to an increase in American global presence and influence.
Step-by-step explanation:
The question asked about the driving forces behind U.S. imperialism during the early 1900s. During this era, several factors contributed to American expansion overseas. Economic motives were a primary cause, as the U.S. searched for new markets and raw materials. Political motives included the desire for increased global influence and strategic positioning. Cultural influences, like the spread of American values and Christianity, also played a role. Taken together, these forces pushed the United States toward a more proactive international stance, with significant impacts on other nations and global politics.