|With a high percentage of British DNA, do I maybe have|
more British branches than I thought?
Similarly, sometimes an ancestor's church or burial place can be a dead giveaway of their origins. Mennonites were normally German or Swiss German, Quakers were English or sometimes Welsh, although in early PA, these two groups were known to convert to one or the other. Presbyterian was often British but it was not unusual for German Reformed churches to become Presbyterian later so it's important to learn what the church's denomination was at the time your ancestors attended. Something like a "First German Church" is a dead giveaway.
You can also get an idea of their origins by their surnames, using tools like Ancestry.com's Name Meaning Look Up. Of course, names could be subject to change but in combination with the above knowledge, it may help narrow down the options. And sometimes, names which weren't anglicized can be a dead giveaway. I have a few names in my tree which are clearly German, even though I haven't found the immigrant ancestor yet, I know that branch is German. Likewise with a few Scottish names. Sometimes, even a first name can be the indicator. I have a "Willem" in my tree which is the Dutch spelling of William so they must be Dutch even if I haven't found their immigrant ancestor yet.
Lastly, you may also be able to get an idea of their origins by looking at the families they married into. While it was not unusual for people of early, small communities to be forced to marry outside their faith or culture, it was more common for people to marry within their faith and culture so who they married might be a good indicator of their cultural background, especially when comparing who their siblings married too.
Combine all of this together and with some branches, you may be able to say with reasonable certainty where they probably originated from. Here's a quick checklist:
- Where/when they lived in the US
- Religious orientation
- Names (surnames or even given names)
- Background of families they married into
Discuss this further at GeneaBoards.