Marrying close to home.

Anyone who has spent time in the parish books of San Giovanni Evangelista learns the same lesson we did while indexing them: in a town the size of Sassano, tucked in the hills 95 miles southeast of Naples, everyone eventually married a relative. Not out of scandal, but out of geography. For centuries the town's marriageable population was, quite literally, whoever lived within walking distance — and more often than not, that meant a cousin.

Using the full Sassano-Bompietro family tree — over 23,000 individuals and 6,000 families, built from the baptism, marriage, and death registers Peter Barbella, Pasquale Cirullo, and I have spent years indexing — we set out to see just how common this really was, and whether it followed the Sassanesi all the way to Federal Street.

It did, and more than we expected.

Of the 4,719 marriages in the tree where both spouses' parentage could be traced, 730 — better than one in six — were between blood relatives close enough to identify: first cousins, second cousins, third cousins, or fourth cousins, some with a generation's remove between them.

What surprised us more was how often it repeated. 416 people in the tree are both the child of a cousin marriage and went on to marry a cousin themselves — three, sometimes four consecutive generations of the same two family lines marrying back into each other, rather than a single instance diluted by outside blood.

And it wasn't left behind when the Sassanesi crossed the Atlantic. Sixty-two of these cousin marriages involve a bride or groom who eventually settled, married, or died in Chicago; another 44, though they took place back in Sassano, produced children who made the crossing themselves. All told, roughly one cousin marriage in seven connects to the Federal Street enclave.

Some of the names will be familiar to anyone who has followed our Home page and Families list. Pietro Abbatemarco and Francesca Trotta, one of the earliest couples in our founding family records, were third cousins. Gabriele D'Amato and Maria Rosa Ricciardone were third cousins as well — a marriage that took some untangling, since Maria Rosa turned out to have married twice: first D'Amato in Sassano in 1889, then, evidently widowed, Michele Riccio in Chicago in 1898.

None of this is unusual for a town like Sassano, and we don't share it to cast any judgment on any family, ours included. Small, isolated communities the world over — mountain villages, island populations, tightly bound immigrant enclaves like the one on Federal Street — show this same pattern, for the same plain reason: the pool of people you were likely to meet, court, and marry was small, and church and family kept you close to those you already knew. For most of Sassano's history, marrying within one's own extended kinship network wasn't the exception. It was close to the rule.

It's worth a brief, honest word on what that can mean medically. Modern genetics tells us that closely related couples have a somewhat higher chance of passing the same rare gene to a child, nudging the risk of certain inherited conditions upward — for first cousins, roughly from a general-population baseline of 3–4% to something closer to 4–6%. The effect fades quickly with distance; second, third, and fourth cousins are genetically close to unrelated pairs. Where it can matter more is exactly the pattern we found here — the same two lines intermarrying across several generations running — which is one thread, among several including poverty, poor sanitation, and limited medical care, that may help explain the high rate of infant and child death visible elsewhere in these records. It is context, not a diagnosis of any one family or descendant.

Mostly, what the numbers tell us is a story we already knew in outline: for two centuries, Sassano was a place small enough that nearly everyone was, in some fashion, everyone else's cousin — and that closeness is written into nearly every family line that eventually found its way to Federal Street.