This Day In History : April 4

1968 United States

Apollo 6 Launched on Saturn V in Unmanned Test

On April 4, 1968, Apollo 6 is launched atop the Saturn V rocket in an unmanned test mission. This critical flight tests the performance of the Saturn V rocket and the Apollo spacecraft, providing valuable data for future manned missions to the Moon.

Also on This Day in History April 4

Discover what happened on April 4 with HISTORY's summaries of major events, anniversaries,
famous births and notable deaths.

Births on This Day, April 4
  • 1802 Dorothea Dix

    American pioneering nurse and social activist who created the first American mental asylums

  • 1842 Edouard Lucas

    French mathematician who worked on Lucas sequences

  • 1846 Raoul Pictet

    Swiss physicist who invented liquid nitrogen and he was a pioneer of cryogenics

  • 1823 Carl Wilhelm Siemens

    German engineer and inventor of laid undersea cables

  • 1887 William Cumming Rose

    American biochemist who discovered threonine (an amino acid)

Deaths on This Day, April 4
  • 1617 John Napier

    Scottish mathematician and inventor of logarithms

  • 1929 Karl Benz

    German inventor, engine designer and automobile manufacturer of Mercedes-Benz

  • 1976 Harry Nyquist

    American physicist and electronic engineer who contributed to communication theory (Nyquist–Shannon sampling theorem; Nyquist rate)

  • 1923 John Venn

    English mathematician who discovered Venn Diagram

  • 1919 William Crookes

    English chemist and physicist who discovered the element thallium

1969

First Artificial Heart Implanted by Denton Cooley

On April 4, 1969, Dr. Denton Cooley performs the first successful implantation of an artificial heart. This groundbreaking procedure represents a significant advancement in medical technology and cardiac care.
1949

NATO Formed as a Military Alliance

On April 4, 1949, the North Atlantic Treaty Organization (NATO) is established through the signing of the Washington Treaty. This military alliance aims to provide collective defense and security for its member countries against potential aggression during the Cold War.
1975

Bill Gates and Paul Allen Establish Microsoft

On April 4, 1975, Bill Gates and Paul Allen officially establish Microsoft, marking the beginning of one of the most influential technology companies in the world. The company's founding revolutionizes the software industry and shapes the future of personal computing.
1960

Senegal Declares Independence from France

On April 4, 1960, Senegal formally declares its independence from France, marking the end of colonial rule. This pivotal moment ushers in a new era of self-governance and national sovereignty for the West African country.
Holiday
Special day
Discover invention