35.6% live in New York
33.3% live in New Jersey
5.6% live in Massachusetts and California
If you don't like people
with the name gilsenan
you should probably go to
New Hampshire (None live there).
Interesting fact: New Jersey
is the state with the most
last name gilsenan per capita.
Check out the popularity
of the last name gilsenan
for each state in the map below.