This is quite definitely Bishop of Landaff, the individual flower head picture should make that clear. Bear in mind I am growing mine in the UK, not the USA. I also grow Bishop of York.
I have an old fashioned English cottage style garden, things either grow or they don't and I avoid like the plague things that need staking. the Bishop has been happily growing in that spot now for 7 years. It is never lifted and has survived in situ 3 of the coldest winters in recent history and the wettest summer too. My soil is light and sandy so it drains extremely well ( not to say too well!) which is how my dahlias cope with being left in place in winter.
