In 1968, Congress authorized the Secretary of Commerce to make a study to determine the advantages and disadvantages of increased use of the metric system in the United States (Public Law 90-472).
The National Bureau of Standards (NBS, now NIST) conducted study which resulted in the Report to the Congress, A Metric America, A Decision Whose Time Has Come and 12-volume substudy reports. The Metric Study recommendations contributed to passage of the Metric Conversion Act of 1975 (15 U.S.C. 205a et seq., amended by the Omnibus Trade and Competitiveness Act of 1988).
NBS SP 345 (PDF). Report to the Congress.A Metric America: A decision whose time has come. Edition: July 1971.
The results of substudies of the U.S. Metric Study were published as an interim series and evaluated for the preparation of the final comprehensive report to Congress. The individual reports of the interim series are:
NBS SP 345-1 (PDF). International Standards. Edition: December 1970.
NBS SP 345-2 (PDF). Federal Government: Civilian Agencies. Edition: July 1971.
NBS SP 345-3 (PDF). Commercial Weights and Measures. Edition: July 1971.
NBS SP 345-4 (PDF). The Manufacturing Industry. Edition: July 1971.
NBS SP 345-5 (PDF). Non-manufacturing Businesses. Edition: July 1971.