This Day In History : December 23

1975 United States

Metric Conversion Act Signed by President Gerald Ford

On December 23, 1975, U.S. President Gerald Ford signed the Metric Conversion Act into law. This act established the United States Metric Board to coordinate and plan the gradual shift from customary units to the metric system, aiming to standardize measurements in commerce and industry.

Also on This Day in History December 23

Discover what happened on December 23 with HISTORY's summaries of major events, anniversaries,
famous births and notable deaths.

Births on This Day, December 23
  • 1732 Richard Arkwright

    English industrialist and inventor who created the spinning frame, built Cromford Mill

  • 1938 Robert E. Kahn

    American internet pioneer

  • 1937 Karol Joseph Bobko

    American astronaut (STS 6, STS 51D, STS 51J)

  • 1822 Sebastian Wilhelm Valentin Bauer

    German inventor and engineer who was a pioneer of submarines

  • 1867 Madam C. J. Walker

    African American entrepreneur who became First American self-made female millionaire

Deaths on This Day, December 23
  • 2004 P. V. Narasimha Rao

    Indian lawyer, politician, activist, 9th Prime Minister of India

  • 1973 Gerard Peter Kuiper

    Dutch-American astronomer who discovered moons of Uranus, Neptune

  • 1907 Pierre Janssen

    French astronomer who discovered helium

  • 1939 Anthony Fokker

    Dutch aviation pioneer and aircraft manufacturer

  • 2013 Mikhail Kalashnikov

    Russian inventor of the AK-47


Giovanni Cassini Discovers Saturn's Moon Rhea

On December 23, 1672, Italian astronomer Giovanni Cassini discovered Rhea, the fifth major satellite of Saturn. This discovery added to Cassini's contributions to the field of astronomy and provided significant insights into the complex system of Saturn's moons.

Tokyo Tower Opens to the Public

On December 23, 1958, Tokyo Tower, a prominent broadcasting and observation tower, opened to the public in Japan. Standing at 333 meters (1,092 feet), it became a symbol of Japan's post-war rebirth and technological advancement, offering panoramic views of Tokyo and serving as a major tourist attraction.

North Tower of the World Trade Center Becomes Tallest Building in the World

On December 23, 1970, the North Tower of the World Trade Center in Manhattan, New York, reached a height of 1,368 feet, making it the tallest building in the world at that time. This milestone in architectural achievement marked New York City's skyline and represented a significant advancement in skyscraper design and construction.

First Human Kidney Transplant Performed

On December 23, 1954, Dr. Joseph E. Murray performed the first successful human kidney transplant at Peter Bent Brigham Hospital in Boston, Massachusetts. The groundbreaking procedure involved transplanting a kidney from one identical twin to another, marking a significant advancement in medical science and organ transplantation.
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