The Alabama Cooperative Extension System (ACES) is the first Extension state program to have an article on Wikipedia. Check it out at http://en.wikipedia.org/wiki/Alabama_Cooperative_Extension_System. The article covers the program areas, structure, and history of Alabama Extension. While extensive, the article remains a work in progress.
Additionally, if you have not already seen it, you may want to glance at Cooperative Extension in Wikipedia.
Jim Langcuster who wrote the article tells me that he has also created a Wikipedia article on the historical panorama of Alabama agriculture.