LEWISTON — One of the defining moments of this project came late in the process, when Sun Journal Chief Photographer Russ Dillingham unearthed four tan, tattered, vertical envelopes, each with a typewritten date and description near the top crease.

These never-before-printed photos from the recently uncovered negatives offer a rare glimpse into what training was like for Ali — in Chicopee, Mass. — and Liston — at the Poland Spring Inn.

Sonny Liston at Poland Spring Inn

The Phantom Punch at 50: Interactive guide to our stories, photos, audio and video

Muhammad Ali at Chicopee, Mass.

Pre-fight weigh-in, May 25, 1965