The old joke in New York City is that the western region of the U.S. starts on the west bank of the Hudson River. Before 9/11, most data centers were often within blocks of each other on the 4 Line.
While they started out like lab spaces in the ’70s, data centers evolved. By the ’90s, most had transformed into enterprise-owned, purpose-built, “island fortresses” with all data held inside. Banking saw the first distributed data centers for DR/backup while processing in their regional markets with a mixed bag of data availability and application latency. Some remember overnight data compilation and the morning reports that appeared on green-lined tractor feed paper as a result. Sarbanes-Oxley forced further physical dispersion.