Opportunity knocking, and infant mortality due in part to overcrowding, led to my various ancestors’ one-way trips to America. Of course, I’ve got almost no cousins with my name, but an awfully large number of (known) cousins. Most of ‘em don’t know they’re related, because most people don’t know anyone older than their grandparents.
I will say that the person who who compiled our genealogy was drunk or mad, a cousin, my father thought that she was touched. I ran across some collateral family in Upstate NY and am slowly getting some idea of what really happened.