incendebant – you are right about this. A&G 556.
The Courtship is not on the same level as Dover Beach. It’s a longish narrative poem in . . . dactylic hexameters! Longfellow was a descendant of John Alden and Priscilla, née Mullins or Mullens.
I checked the Courtship and it is longish so it might have to wait a bit before I can tackle it. But I read bits of it and I quite liked it. I didn’t know it was a family affair.