History of Maine Freemasonry (1762-1970) by Ralph J. Pollard
Full text of the book, including the pictures and biographies of Grand Masters (Note: There were two editions of this book. The first covered 1762-1945 while the second added pages covering the period 1946-1970. The entire book is now online!
Proceedings of the Centennial Celebration of the Grand Lodge of Maine compiled by Charles B. Davis, Grand Secretary