Final answer:
The Coast Guard is the smallest branch of the U.S military, playing a vital role in maritime safety and security. Each branch operates under civilian control with the President as Commander in Chief.
Step-by-step explanation:
The smallest branch of the U.S. military is the Coast Guard. The armed forces of the United States consist of five branches: the Army, Navy, Air Force, Marine Corps, and Coast Guard. Each branch serves a unique role in the security and defense of the country. Even though the Coast Guard is smaller in personnel numbers compared to the other branches, it plays a pivotal role in maritime law enforcement, search and rescue, and maintaining the security of America's borders and waterways. The Constitution ensures that all these branches, regardless of size, operate under civilian control, with the President acting as the Commander in Chief.