What forces shaped Dallas from its humble 1841 beginnings into the city we know today? We’ll look back this hour with the perspective of 125 years of news-gathering with Bob Mong, editor of The Dallas Morning News and David Woo, photo editor of the newspaper’s 125th anniversary book, “Frontier to Top Tier: A Photo Retrospective from the Dallas Morning News and its Readers” (Pediment Publishing, 2010).