The thing you are researching may have already been found and published by a distant relative on ancestry.com.

Go to the ancestry.com public member tree search page, and then enter the information you know about the ancestor for whom you are searching.

I’ve found this search page didn’t help me much, usually. If you get their DNA test done, they will then suggest possibly related ancestry.com users, and those users’ published family trees are much more likely to contain some of your shared ancestry. I wrote another tip on donig that.