So I went with Norgate. It has been mentioned a few times in other threads. Thanks a lot for your help.
I don't think this is quite true. I subscribe to CSI and pay $540/year for all futures at all exchanges all around the world. Just now I checked and, yes, sitting in my CSI folder on my hard drive, there is Corn historical data from 1949. (more than 25 years ago).Quote from jeffrey.johnson:
Also, for some reason they (CSI) only offer a maximum of 25 years of data in total.

By CSI you mean http://www.csidata.com/ I imagine.
Thanks for your information, but I find them to be expensive, because after paying the subscription fee, I still have to pay almost another $200 ($10 x 20 years) to get the data going back to 1985. Also, for some reason they only offer a maximum of 25 years of data in total.