Greenway earned a Silver Star for his courageous service at the Battle of San Juan Hill. He is referenced on numerous occasions by Roosevelt in his book "The Rough Riders" and a book of Greenway's own correspondence was turned into a book entitled "It Was the Grandest Sight I Ever Saw: Experiences of a Rough Rider As Recorded in the Letters of Lieutenant John Campbell Greenway". In his book, "The Rough Riders", Roosevelt said about Lieutenant Greenway: