I believe most left from Boston and one or two from ME.
You may be right, but it proves that Boston was not the intended target. Just the most convenient city to hop on a shuttle flight. I have flow the Boston Shuttle many times. Pre 911, the security was a joke. But then, I got on the first flight from NY to LA exactly a week before 911 with a freaking COMMANDO KNIFE in my backpack (I forgot it was there) and nobody said a word to me. Presumably this was the exact same security crew as a week later.