Complex sentence: A guerilla movement enjoying considerable support from the population in the eastern provinces of El Seibo and San Pedro de Macorísand and having knowledge of the local terrain fought against the U.S. occupation from 1917 to 1921.
Split into simpler sentences: A guerilla movement enjoyed considerable support from the population in the eastern provinces of El Seibo and San Pedro de Macorís. Having knowledge of the local terrain, they fought against the U.S. occupation from 1917 to 1921.