The Hollerith Machine
census.govHolleriths were also used to coordinate elements of the Holocaust[1].
There's a beautiful exhibit of one of these in the Computer History Museum. Just saw it last weekend.
The Holleriths (later IBM Tabulators) were also used extensively in Bletchley Park and the Heliopolis station as part of the technique for cracking Italian Air codes - explaining why there's one or two knocking about in the National Museum of Computing in Bletchley.
There's a great segment in the documentary series Connections that discusses the Hollerith Machine: https://youtu.be/_mT_futz23s?t=2m37s