Alfred Thayer Mahan was the one who took the position that the United States should establish naval bases outside of the country. Alfred was named "the most important American strategist of the nineteenth century", and was known for being a naval officer for most of his life.
The Industrial Revolution cut the time needed to manufacture clothing and other goods. It also industrialized trade, seeing as how most of the traded goods came from factories.
West Indies and focus particularly on the atrocities committed by the colonizers against the indigenous peoples. So he just felt the need to do it.
