Longfellow makes a big deal about looking back at the past in "Paul Revere's Ride." He definitely gives us an action-packed version of the night's events, but he wants us to remember that this was history even when he wrote it. He obviously thinks it's important that we keep the memory of the Revolutionary times alive, so he wrote a poem that's entertaining but also carries a little history lesson with it. Think of this like pre-TV "Schoolhouse Rock," the 1860 version of educational edutainment.
Longfellow's poem constantly plays with time and manages to link past, present, and future in interesting and unexpected ways.
"Paul Revere's Ride" creates a fantasy version of the past that changes the facts while pretending to offer a historical lesson.