Complex sentence: A month later, she arrived in the Panama Canal Zone; embarked the 7th, 17th, 20th, 43d, 51st, and 55th companies of Marines; transported them to Santiago de Cuba; then sailed for Philadelphia, arriving on 29 May 1917.
Split into simpler sentences: A month later, she arrived in the Panama Canal Zone and embarked the 7th, 17th, 20th, 43d, 51st and 55th companies of Marines. She transported them to Santiago de Cuba and then sailed for Philadelphia, arriving on 29 May 1917.