I will guess and say a Eupatorium species. There are over 800, but very common in your region. Eupatorium - Wikipedia, the free encyclopedia If you scroll down at that link, the hemp-agrimony looks kind of like what you have pictured. (Yankeeweed) But the hemp-agrimony is probably not it since it's primarily a European plant.
Now that you mention it, that's exactly what I think it is. It's about 4-1/2 ft high now, up to my collarbone. I'll post pictures when it blooms because it is beautiful and smells lovely. It's a hardy weed
We'll just call it a zombie weed. Seems fitting. Hey...we need a zombie emote. This one isn't gonna cut it, lol.
What you have pictured is definitely a variety of asclepias, for sure. http://en.wikipedia.org/wiki/Asclepias