Final answer:
The American poet born in Maine, educated at Bowdoin College where he later taught, and who also served as a professor at Harvard before retiring to focus on his poetry is Henry Wadsworth Longfellow.
Step-by-step explanation:
The American poet born in Maine, educated at Bowdoin College where he later taught, and who also served as a professor at Harvard before retiring to focus on his poetry is Henry Wadsworth Longfellow. He is known for notable and lengthy poems such as "Paul Revere's Ride," "The Song of Hiawatha," "The Courtship of Miles Standish," and "The Children's Hour."