Holly Ann Weathers
I had no idea I was descended from Mayflower passengers!
How I found out was that I built out my family tree on Geni, from myself backwards in time, using census data (free from familysearch.org) mostly. Also Civil War records, Daughter's of the American Revolution records, land transfer records, etc. -- the standard stuff of genealogy.
Then with an ancestor around 1750, I joined "the Big Tree" and "hooked onto" existing Geni profiles.
From *those* family lines I was into Old New England (never knew this).
Once I was in Old New England settlers, it was just a matter of time -- and tracing marriage events -- before I found my Mayflower ancestors.
I'm still finding more as we "clean up" the tree! I'm now a much closer relative to, for instance, Thomas Rogers, "Mayflower" Passenger than I ever knew ( 8th great uncle's great grandfather currently ...)