Today in US history on April 5: From presidential power and scientific standards to war, conflict, and space exploration

April 5 in US history highlights a range of pivotal developments spanning early governance, scientific standardization, global conflict, and modern military and technological milestones. From the first use of power to Cold War-era tensions and advances in , the events of this day reflect key moments that have shaped America’s political authority, scientific progress, and international role.

1792: Washington issues his first presidential veto

In 1792, US President George Washington exercised the first presidential veto, rejecting a bill concerning the apportionment of congressional seats. The decision set an early precedent for the use of executive veto power in the United States.

1893: standardizes US measurements

In 1893, the Mendenhall Order was published, defining US customary units such as yards and pounds in terms of metric standards like meters and kilograms. The move helped align American measurement systems more closely with international scientific standards.

1964: General dies at 84

In 1964, Douglas MacArthur, one of the most prominent of the 20th century, died at the age of 84. He played a key role in both World War II and the Korean War.

1986: Deadly prompts US retaliation

In 1986, a bombing at a nightclub in West Berlin popular with US soldiers killed an American serviceman and a Turkish woman, injuring dozens. The attack, later linked to Libya, led to US retaliatory airstrikes.

1991: Atlantis mission STS-37 launched

In 1991, Space Shuttle Atlantis lifted off on mission STS-37, tasked with deploying the Compton Gamma Ray Observatory. The mission played a key role in advancing the study of high-energy space phenomena.