Bailyn may be best known to Canadianists for his sympathetic -- or at least detached -- biography of the American loyalist Thomas Hutchinson, last royal governor of Massachusetts. I've given a few talks on Loyalism to American audiences, and sometimes been struck by the "aren't we naughty" frisson about them: "Oooh, we're going to talk about the bad guys!" Bailyn was working against that instinct when he published The Ordeal of Thomas Hutchinson in 1968 -- and was accused of writing about loyalism in order to criticize the revolutionary tendencies then roiling the United States.
Bailyn is credited with helping revive scholarly interest in colonial American history in the 1950s, simply by taking its seriously, not as a collection of patriotic legends. His master work in that regard was The Ideological Origins of the American Revolution. Later in his career, he was criticized for being too oriented to high culture, ideas, ... and white people. His massive project The Peopling of British North America was alleged to ignore that people were there before British North America. This is a note on that controversy from this blog five years ago.