March 29

Swedish colonists establish New Sweden, the first Swedish colony in North America, near present-day Wilmington, Delaware.

Swedish colonists led by the Dutch-born governor Peter Minuit established New Sweden along the Delaware River near present-day Wilmington, Delaware, founding the first and only Swedish colony in North America. The small, sparsely populated settlement struggled to attract enough colonists and was ultimately absorbed by the larger neighboring Dutch colony of New Netherland roughly seventeen years later.

King Gustav III of Sweden dies after being shot at a masquerade ball, an assassination later dramatized in opera.

King Gustav III of Sweden was shot by a group of conspirators during a masked ball at the Royal Opera House in Stockholm and died of his wounds weeks later. The dramatic assassination later inspired Giuseppe Verdi's opera "A Masked Ball."

Construction begins on the Cumberland Road, the first major U.S. federal highway.

Construction began on the Cumberland Road, later known as the National Road, the first major infrastructure project funded directly by the U.S. federal government under authority granted by Congress. Eventually connecting Cumberland, Maryland, to Illinois, the road became a vital artery for westward migration, trade, and settlement during the early nineteenth century, predating the railroad era.

Britain formally annexes the Punjab region of India after defeating the Sikh Empire.

Following its victory in the Second Anglo-Sikh War, Britain formally annexed the Punjab region of the Indian subcontinent, incorporating the once-powerful Sikh Empire's territory directly into British India. The annexation ended Sikh political sovereignty in the region and brought under British control valuable agricultural lands and a large population that would later supply many soldiers to the British Indian Army.

Queen Victoria grants royal assent to the British North America Act, paving the way for Canadian confederation.

Queen Victoria gave royal assent to the British North America Act, the constitutional legislation drafted following negotiations among British colonial leaders that established the Dominion of Canada by uniting the provinces of Canada, Nova Scotia, and New Brunswick under a federal system. Canada formally came into existence as a confederation on July 1 of that same year.

The U.S. Army officially adopts the Colt M1911 pistol, which remained in service for over seven decades.

The United States Army officially adopted the Colt Model 1911 semi-automatic pistol as its standard sidearm following extensive trials that tested its stopping power and reliability against various competing designs. Created by prolific firearms designer John Browning, the pistol proved so durable and effective that it remained in official U.S. military service for more than seven decades.

Adolf Hitler receives overwhelming approval in a plebiscite ratifying Germany's remilitarization of the Rhineland.

In a plebiscite widely regarded by historians as manipulated and held under pervasive conditions of intimidation and propaganda, German voters overwhelmingly approved Hitler's recent remilitarization of the Rhineland in direct violation of the Treaty of Versailles. The lopsided result bolstered his domestic standing considerably and emboldened him to pursue further aggressive territorial moves across Europe in subsequent years.

Lieutenant William Calley is convicted by a court-martial for his role in the My Lai massacre in Vietnam.

A U.S. Army court-martial convicted Lieutenant William Calley of premeditated murder for his role commanding the platoon responsible for the My Lai massacre, though his sentence was later substantially reduced and he served only a few years under house arrest.

The last United States combat troops leave Vietnam, formally ending direct American military involvement.

The last American ground combat troops departed South Vietnam following the Paris Peace Accords, formally ending direct U.S. military engagement in the war, though American support and involvement in the broader conflict continued in various forms until Saigon's fall two years later.

Ireland becomes the first country in the world to ban smoking in all workplaces, including pubs and restaurants.

Ireland became the first country in the world to implement a comprehensive nationwide ban on smoking in all enclosed workplaces, including pubs and restaurants long central to Irish social life, despite initial industry warnings of economic harm. The pioneering public health measure proved broadly popular and durable, and numerous other countries subsequently adopted similar bans in modified forms.