The social reform movement of the 19th Century was, as you point out, a precursor of today's PC movement. Many antebellum abolitionists also favored prohibition of alcohol, equal rights for women, universal and compulsory public education, and even vegetarianism. All these strains of social uplift are still visible in 2003, although the anti-alcohol zeal seems to be focused on tobacco, to a large extent. Anhueser-Busch and McDonald's executives probably have sleepless nights in fear that the full force of PC wrath may someday turn from tobacco onto beer and high cholesterol foods.
However, to call it a Protestant movement is inaccurate. The "social uplift" movement largely arose out of the Unitarian churches, which are neither Protestant nor Christian, and was also supported by other freethinkers, people whom we would now call secular humanists. Though from a Baptist background, Lincoln was not a Christian believer during most of his adult life. (There is some evidence that he converted to the Christian faith while in the White House.) This reform movement did have support in what might be labelled the "broad church," essentially proto-liberals who paid lip service to the Reformation creeds but who accepted the social engineering schemes of the reformers as a means of establishing a kingdom of God on earth. However, these people rejected, by their vain schemes to create heaven on earth, the core Christian doctrines oultined in the early ecumenical creeds as well as the Reformation distinctives.
I'm certainly no theologian or church historian, but I do think that a look at Calvin's Geneva, Knox's Scotland or Winthrop's Massachusetts Bay would raise serious questions about your interpretation. A look at the Prohibitionist Pary, the YMCA and the Methodists would also call the view of social uplift and reform as a unitarian development into question.