Complex sentence: The U.S. retained dozens of military bases, including a few major ones, and independence was linked to legislation passed by the U.S. Congress that was designed to ensure that the Philippines would remain an economic ward of the U.S., for the time being.
Split into simpler sentences: The U.S. retained dozens of military bases, including a few major ones. In addition, independence was qualified by legislation passed by the U.S. Congress to ensure that the Philippines would remain an economic ward of the U.S., for the time being.