The relevant contents of the five famous allusions of friendship are as follows: - Abraham Lincoln and John F. Kennedy: Both Abraham Lincoln and John F. Kennedy were well-respected leaders in American history. They established deep friendships with their friends at different times in history. The friendship between Lincoln and Kennedy was called "one of the greatest friendships in American history." - Mark Twain and John Lennon: Mark Twain and John Lennon were famous in the history of British literature. Their friendship was called "one of the greatest friendships in literature and art." - He and Johann Strauss were famous musicians and composer. Their friendship was called " one of the greatest friendships in music history." - George Washington and Benjamin Harrison: George Washington and Benjamin Harrison were two heroes of the American Revolutionary War. Their friendship was called " one of the greatest friendships in American history." - Robert Frost and Edward F. Kennedy were famous American politicians in the 1920s and 1930s. Their friendship was known as " one of the greatest friendships in American political history."