Background
According to the document:
Almost forty years ago, United States leaders created a hybrid National Reconnaissance Office (NRO) to meet the unusual intelligence demands of the nuclear age and the Cold War. The chain of events began when President Dwight D. Eisenhower and a few confidants undertook national and international initiatives between 1953 and 1961 intended to help preclude a surprise nuclear attack.
Among them, they approved for development remarkable overhead technical systems that could collect reliable intelligence about the military equipage and disposition of Soviet forces; in the process they opened the Soviet Union to American scrutiny.
During this period they also established the national policy and organizations needed to guide and execute a newly-emergent enterprise: astronautics.
Document Archive
The National Reconnaissance Office: A Brief History of its Creation and Evolution, April 1999 [4 Pages, 0.8MB]
https://documents.theblackvault.com/documents/nro/F15-0025.pdf
