Maggie, that's great I was able to id the last 2 you posted.* With this last pic I'm not sure as there are no flowers and the pic is a bit small.* Considering the size (I can't tell just how tall, but they appear to be at least 3' tall), the time of year and the fact that it appears about to form flowers, I do have a couple of guesses.
Aster - there are some named cultivars of these natives as well as the wild species:
New York aster aka Aster novi-belgii aka Symphyotrichum novi-belgii grows 3' to 4' tall in a purple/lavender color.* It is sometimes called michaelmas daisy.
New England aster aka Aster novae-angliae aka Symphyotrichum novae-angliae grows 3' to 7' tall and has more flower petals then the New York aster.* Flowers can be rosy pink to lavender/purple.
One of the asters I have in my garden is Aster novae-angliae 'Andenken an Alma Pötschke' aka Alma Potschke aster with it's bright rosy flowres.
If you scroll down here you can see some of the named varieties of aster.
Joe Pye weed aka Eupatorium purpureum is another native that gets quite tall in my garden and grows to 6' or 7' tall.* A real butterfly magnet.* There are several different species of this native.* The cultivated ones tend to stay in a tighter clump then what I'm seeing in your picture, so this may not be it.
I'd love to see a picture of the flowers.