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).
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:
Becoming Familiar with SI | Everyday Estimation | Metrication FAQs | Prefixes | Metric Kitchen | SI Education and Training | SI Publications | Understanding Metric | Writing with Metric Units | National Metric Week | NEST-R (STEM Registry) | NIST Education Resources