Do you know where he was born?I check the 1930 census for Jackson Co, GA and there were no BARTLETTs there at that time. The 1940 census will become available in April 2012, so if you know the birthplace we can look for any BARTLETTs there in 1940...
Also you can take a Y-DNA test. You got your Y-DNA from your father, who got it from his father (Walter?), who got it from his father.We know the Y-DNA signature of 5 different BARTLETT lines who lived in GA (one includes Josiah who signed the DOI). If your Y-DNA test matches any one of these (or 15 other lines for which we already have matching Y-DNA), then at least you would known which lines to follow.
Let me know if you are interested in DNA testing - there is a sale on now to 31 Dec - it would make a great present for yourself and your family.
You can look at www.familytreedna.com for more info. Put BARTLETT in the search box and find our project... Or contact me for any questions - send me an email for info on pricing.