Bunker Hill

Another rather unfair question, IMHO. I'm not saying it's wrong; but it depends what you mean by a pitched battle. What do you mean? I don't know!

The Battle of Bunker Hill took place in the hills around Boston, on 17 June 1775. (Most of the action was actually on Breed's Hill.) Earlier military actions in the American War of Independence include Lexington and Concord (both 19 April 1775), the capture of Fort Ticonderoga (10 May), the Battle of Chelsea Creek (27–28 May) and the Battle of Machias (11–12 June). It's true that several of these are best described as skirmishes, and Machias was a naval engagement (and therefore probably can't be called a pitched battle); and it's true that in most if not all sources that do name the first pitched battle, that battle is Bunker Hill. But not all sources distinguish between pitched battles and other battles.

I'm prepared to believe that if you're a military historian, there's no doubt that Bunker Hill was the first pitched battle. But this is supposed to be a General Knowledge quiz.