I think one of the reasons we've been able to trace so far back is that most of my family lines in this country start early in the 1600's, so there's been little opportunity for major disruption of records due to wars. Some of the records come from English shipping manifests that have good documentation of passengers who came over to the colonies. For example, the earliest birth I've seen so far in this country was 1613, but many in the mid 1600's.

So when someone boasts that their ancestors came over on the Mayflower, I can reply that mine met the boat.