I've come across ancestry.com. You have to subscribe to get most of their data ... and their top-of-the-line subscription is $200! Not sure how helpful the cheaper ones would be ... I'd rather pay $80 for a truly helpful source than $40 for a very limited one but that's still more than I'd wanted to invest at this point ... *sigh*
Btw, most of my great-grandmother's family was from a place near Pilot Mountain, NC, which is the inspiration for Andy Griffith's Mt. Pilot. I don't know if many people realize that there really is a mountain by that name.
My mom bought the $100 and found it useful. She's also gone to Pennsylvania three times to look at gravestones and records.
If you've found ancestors back to 1794, you may want to find a group online or something to see what has been done. Or join a family association. I'm not so sure the US census would help you much.