Yet, there probably were worse draughts within past 200 years. Tree rings and river bed markings can easily prove this. `On Record` is a little deceiving.
- There are many research available that used tree rings to determine past draughts. And yes there were much worse and prolonging ones. Some research goes as far back as a millennia.
- Yo do not need to kill a tree to get ring information. A drill is sufficient.
This may be useful too http://drought.memphis.edu/OWDA/