I am guessing that most of the genealogists who live in the states that have digital archives are unaware of their state's websites and as even more likely, those outside of the state are even less knowledgeable. In the state of Alabama, there is the Alabama Department of Archives and History Digital Collections as well as the AlabamaMosaic.org and the Encyclopedia of Alabama. All three of these websites contain significant collections of digital resources about the people and history of Alabama.
The Encyclopedia of Alabama is described as follows:
The Encyclopedia of Alabama is a free, online reference resource on Alabama’s history, culture, geography, and natural environment. It was developed by the Alabama Humanities Foundation and Auburn University with generous financial support from across the state. Auburn University hosts EOA's editorial office through the Office of University Outreach, in partnership with University Libraries and the Office of Information Technology.
The Encyclopedia of Alabama joins a number of other state-sponsored online encyclopedias. Here is the list from the website:
ConnecticutHistory
Encyclopedia of Arkansas History & Culture
Encyclopedia of Chicago
Encyclopedia of Cleveland History
Encyclopedia of Greater Philadelphia
Encyclopedia of Oklahoma History & Culture
Encyclopedia of Puerto Rico
Encyclopedia Virginia
Guampedia
Handbook of Texas Online
HistoryLink.org: The Online Encyclopedia of Washington State History
Kansapedia
KnowLA, The Encyclopedia of Louisiana
MNopedia
NCpedia
New Georgia Encyclopedia
North Carolina History Project
Ohio History Central
Online Nevada Encyclopedia
Oregon Encyclopedia
Puerto Rico Encyclopedia
Tennessee Encyclopedia of History and Culture
The Canadian Encyclopedia
Utah History Encyclopedia
West Virginia Encyclopedia
WyoHistory
Another extensive list of online encyclopedias is found in the Wikipedia article entitled, "List of online encyclopedias." Another list is found on the Library of Congress website in an article entitled, "State Digital Resources: Memory Projects, Online Encyclopedias, Historical & Cultural Materials Collections." A list almost identical to the one above is found on a website sponsored by the National Endowment for the Humanities called EDSITEment! or edsitement.neh.gov.
When you are doing research in a particular state, you might want to investigate the online, free resources provided by the state's government.