Tracing Family roots

[Piper]

My father was an avid genealogist. He spent the last 25 or so years of his life tracing our family tree. I did a bit of leg work for him from time to time, and his older brother frequently worked with him for the final 10 years. The results are interesting. He traced a Welsh line back to 3 digits (600's I believe), and there are other lines he couldn't get back beyond 1920 or so in South Philly. Seems our family name (Young) comes from either Ireland or Scotland. My father initially listed the earliest Young he found as coming from Kincardine, Ireland. I've been unable to find such a place, but there is a Kincardine Shire in Scotland, with a large number of Youngs in the area. But the family's been in America for a while. When people ask me if I'm Scottish (big, ruddy faced, bearded piper in a kilt), I explain that my ancestor may have come from Scotland, but we have the records of his marriage in Philadelphia PA, in 1742, so I figure that makes me an American.
I know some of the earlier genealogical records tend to be suspect, but the Welsh line was researched by my Uncle, while he was over there a few years back. He lucked onto some old church records. From what I understand, under the old laws you could be held responsible for fines and assessments incurred by certain of your relatives, so they tended to keep pretty good records. Don't know if that's actually the case, but it would be an incentive to keep decent records.
Another interesting tidbit that turns up is that we've had family on both sides of every conflict this country has had from the French & Indian War, through WWII.