For the past two days, I've been going through this site. By doing so, I've managed to find my great-great grandparents!
All I done was go through census that have been done every 10 years since 1830's. I done my grandparents, found their dates of birth, went to the following census to find their parents names and dates of birth. Then I took that, went to the year that they were born to the following census to find their parents names and dates of birth.
I have found a new part of my family that I never knew or knew that existed. I even found that part of my family was retired from the railroad, another was a coal miner in the 1800's, family that we never knew existed.
I also learned of my biological father's side of the family. Not one that I would recommend to some, as it brought through a whole lot of horrible heartaches. I know now, that I have a half-sister, and another half-sibling that was never recorded or that my biological father never claimed. I found that by doing so, he was not the hero that he should had been as he served in WWII, his father in WWI. I found that he was arrested and sent to prison for the attempted murder of my half-sisters mother after her birth, she was only 9 days old. This took place in June of 1960. My half-sister was 18 when I was born. My biological father, is not a hero as he should had been, but a monster. He was known as the one handed farmer or one handed moonshiner. This took place in Nashville, TN.
I've found more on FindMyPast.com than I've ever found on any other site for learning of whom your family is or was. I recommend you check this out. You can get 1 month for close to $10 to find a whole lot out that you never knew. I will be doing more research as time permits, and hope you'll do the same thing for your family.