Complex sentence: Olivia Sage also organized the effort to fund and build the John Jermain Memorial Library in Sag Harbor in honor of her grandfather, Major John Jermain, who fought in the American Revolution.
Split into simpler sentences: Olivia Sage also organized the effort to fund and build the John Jermain Memorial Library in Sag Harbor. It was named in honor of her grandfather Major John Jermain, who fought in the American Revolution.