Complex sentence: Roosevelt Campobello International Park preserves the house and surrounding landscape of the summer retreat where, in August 1921, future president Franklin D. Roosevelt was stricken with poliomyelitis at the age of 39.
Split into simpler sentences: Roosevelt Campobello International Park preserves the house and surrounding landscape of the Roosevelt family summer retreat. It was here in August 1921, future president Franklin D. Roosevelt was stricken with poliomyelitis at the age of 39.