There are two inaccuracies in your statement. First, World War II began in 1939, not World War I. Second, the Americas are typically split into North America, Central America, and South America. Rather than different groups of Americas responding, you may be referring to different groups within the Americas. For example, in the United States, there were various views and responses within the country to the start of World War II in 1939. Some individuals and groups were in favor of immediately joining the war, while others were opposed. The general public sentiment shifted over time, with a growing belief in the need for intervention as the conflict escalated.