Between 1946 and the founding of the National Science Foundation in 1950, the Office of Naval Research was the federal government's only agency whose principal mission was the support of basic research.
In the aftermath of World War II, Americans credited big science, pure science, with having done much to win the war. Even given the traditional American fascination with invention, progress and technology, the Second World War forced technical and scientific advance into popular thinking about defense to an unprecedented extent. People remembered Pearl Harbor and never wanted to be surprised like that again, and saw technology as a guarantor of security. Basic science shared the aura of victory.
The original permanent basic research establishment, ONR, evolved over the last 60 years into something more diversified and in some respects more accountable to its customers than its founders envisioned.
The greatest change occurred in fiscal year 1992, when the Office of Naval Technology (ONT) and the Office of Advanced Technology (OAT), separate agencies that reported to the Chief of Naval Research, were folded into ONR.
With the absorption of ONT and OAT, ONR was "reinvented" and became responsible for applied research and technology development. Since then ONR has worked to integrate the research it supports and to produce an investment portfolio that does justice to its several constituencies: Congress, the fleet, the force, industry and universities.
– Fact sheet from ONR's history page: http://www.onr.navy.mil/about/history/docs/st_invest_pov.pdf.