Pendarvis Family Genealogy Forum
You may want to check with the Florida Bar of Attorneys. I am not sure how far back its records go, but many state bar associations came into being during the early to mid 1800's. If the Florida Bar existed around 1815, it may have some information on the James Pendarvis. Similarly, there were many County Bar Associations existing during that time, so the same would apply to the Alachua County Bar Association. Another lawyer resource is Martindale-Hubbell, which is a private company that advertises that it has been existence and listing attorneys' names and practice areas for 130 years. It's website is www.martindale.com
Good luck, and by the way, thanks for your hard work on the county websites.