My suggestion would be to try and track Rufus and John's location through the use of the federal census information. The first US federal census was in 1790 so Rufus would be roughly around 19 years old if he was born in 1771. I would use this as a starting point for your research and then John should show up in the 1810 census if he was born in 1806.
You can access the federal census data through Ancestry.com. If you do not have Ancestry membership, I would check with your local library because they often subscribe to Ancestry.com. If your local library does not have a subscription to Ancestry, then all National Archives and Records Administration's buildings provide access to Ancestry.com onsite.
One other potential place to look would be in Family Search. I have provided a link to it below. Hope this helps!
Textual Reference Operations (RDT2)
National Archives in College Park, MD