In the last 35 years, the disaster and humanitarian communities have evolved rapidly in two parallel cohorts. The disaster enterprise in the US and Latin America grew up in the 1970s in response to a series of major earthquakes, hurricanes, and forest fires, culminating with the nuclear disaster at Three Mile Island and the formation of the Federal Emergency Management Agency (FEMA) in 1979/80. The Disaster Program at the Pan-American Health Organization also took form in the 1980s.

The humanitarian enterprise can be traced to the Biafran War of 1968/69, where a range of international, non-governmental organizations (NGOs) converged to respond to support a population that was fleeing a civil war and famine. In the years since, drawn to refugees and internally displaced persons in war circumstances as varied as Angola, Afghanistan, and Bosnia, the humanitarian community has expanded in numbers, reach, and budget.