Historedia
AmericasEvent

Metric Act of 1866

When
1866
Where
House Committee on Coinage, Weights, and Measures; U.S. Congress; United States
Episodes
3

The Metric Act of 1866, known as the Kasson Act, legalized the use of the metric system in U.S. commerce and established official conversion tables from customary units. Championed by Representative Kasson, the bill passed the House in May and the Senate in July 1866, becoming law upon President Johnson's signature on July 28.

Episodes

  1. 1866 · House Committee on Coinage, Weights, and MeasuresKasson Act Proposal

    Representative Kasson proposed the Metric Act, citing its utility in arts and trades, to protect metric use in commerce.

  2. 1866 · United StatesLegal Definitions and Tables

    The Act established official conversion tables from customary units and defined the metric system for legal use.

  3. May 17 - July 28, 1866 · U.S. CongressCongressional Approval

    The House passed the bill in May 1866, and the Senate approved it in July, leading to presidential signature.

Background and detail

Background. U.S. customary units, standardized in 1832, derived from English units used before independence. The Metric Act provided legal protection for metric use in commerce, addressing its existing application in arts and trades. This legislation created official conversion tables, bridging the gap between customary measurements and the metric system.

Legislative Process. Representative Kasson, Chairman of the House Committee on Coinage, Weights, and Measures, proposed the act. The House passed the bill on May 17, 1866, followed by Senate approval on July 27. President Andrew Johnson signed the legislation into law on July 28, 1866, finalizing its enactment.

Content and Definitions. The Act included an obsolete definition of the metric system and tables of units. These tables provided official conversions from U.S. customary units. The original document's definitions were later replaced by modern SI standards, though the 1866 Act's conversion tables remained significant for historical reference.

People involved

Sources

  1. Metric Act of 1866 Wikipedia, revision of 2024-12-27
  2. United States customary units Wikipedia, revision of 2026-09-29

Machine-drafted from the cited Wikipedia passages and checked by a reviewing model, not by a human editor. Every passage cites the revision it was written from; dates and places follow those passages.