During the late 1800s and early 1900s, a man named Alfred Thayer Mahan had a tremendous influence on American policies. Mahan argued that naval power was the key to a country’s strength. Strong countries had to have strong navies. In those days, naval vessels were powered by steam which was produced by coal. This meant that a country had to have many bases around the world where its wships could get coal and other necessary supplies.
The US wanted to be a strong country. Therefore, it needed to have bases in various areas of the world in which it wanted to project its power. This helped lead the US to do things like taking Hawaii and the Philippines so that it could use those places as bases for its navy.