Complex sentence: Captains of all Exeter's athletic teams were awarded the right to display Exeter's "E" on their sweaters, along with a certificate from the "Phillips Exeter Academy Athletic Association" authenticating their rights in writing.
Split into simpler sentences: Captains of all Exeter's athletic teams was awarded the right to display Exeter's "E" on their sweaters. Along with a certificate from the "Phillips Exeter Academy Athletic Association" authenticating their rights in writing.