Longfellow was a poet and a mythologist in the sense that he created wonderful poetry about our history, to create a warm sense of connection with it.
He was not, however, trying to be an accurate historian. This is why Sarah Palin was unfairly mocked after repeating what she’d heard at a historical presentation of Paul Revere’s ride.
My ancestors were John Alden and Priscilla Morrison, so we listened to Longfellow’s “The Courtship of Miles Standish” and enjoyed it very much, but we giggled at the historical outlandishness.
This is a great book:
http://www.amazon.com/Paul-Reveres-David-Hackett-Fischer/dp/0195098315
My understanding is that Palin was mocked for saying Revere told the British that the militia was gathering, which he did when captured by a British scouting party and his horse taken. He was released when the scouting party fearing being attacked by a large force of militia returned to their base.
I am also a direct descendant of John Alden and Priscilla Mullins through their great-granddaughter, Sarah Alden who married Seth Brett. Yes, Longfellow’s “The Courtship of Miles Standish” is fiction.