Why the moon was the first celestial body selected for investigation by the US?

The Moon was the first celestial body selected for investigation by the US primarily due to its proximity and visibility from Earth, making it a relatively accessible target for exploration. Additionally, the Cold War space race with the Soviet Union heightened the urgency to demonstrate technological and scientific superiority, and the Moon represented a significant milestone in human space exploration. The Apollo program aimed not only to achieve a manned lunar landing but also to gather valuable scientific data about the Moon's composition and geology.