In History, Today on January 1

Portuguese explorers, led by Pedro Álvares Cabral, become the first Europeans to sail into Guanabara Bay, which they initially mistook for the mouth of a river. They named it Rio de Janeiro.

The first traveler's cheques, which can be used in 90 European cities, are issued by the London Credit Exchange Company.

During the American Revolutionary War, General George Washington hoists the Grand Union Flag, the first national flag of the United States, at Prospect Hill.

The legislative union of Great Britain and Ireland is completed to form the United Kingdom of Great Britain and Ireland.

Haiti gains independence from France, becoming the first independent nation of Latin America and the Caribbean, and the first post-colonial independent black-led nation in the world.

The Emancipation Proclamation issued by President Abraham Lincoln takes effect, freeing slaves in Confederate states during the American Civil War.

Ellis Island begins processing immigrants to the United States, becoming the nation's busiest immigrant inspection station.

The Commonwealth of Australia is established as six colonies federate, marking the birth of modern Australia.

Fidel Castro's forces overthrow the government of Cuban dictator Fulgencio Batista, marking the beginning of Castro's rule in Cuba.

The United Kingdom, Ireland, and Denmark enter the European Economic Community, which later becomes the European Union.

Czechoslovakia peacefully splits into the Czech Republic and Slovakia in what is known as the Velvet Divorce.

The euro currency was officially introduced in 12 European Union countries, marking a significant step in European economic integration.

The Republic of Ireland becomes the first country in the world to ban smoking in all workplaces, including bars and restaurants.

Bulgaria and Romania joined the European Union, expanding the EU to 27 member states.

Cyprus and Malta adopted the euro as their official currency, further integrating into the Eurozone.

Slovakia adopts the Euro as its official currency, becoming the 16th member of the Eurozone.

Spain assumed the rotating presidency of the Council of the European Union, focusing on economic recovery and the implementation of the Lisbon Treaty.

Estonia adopts the Euro as its official currency, becoming the 17th member of the Eurozone.

Latvia adopted the euro as its official currency, becoming the 18th member of the Eurozone.

Lithuania adopted the euro as its official currency, joining the Eurozone as its 19th member.

Antonio Guterres began his term as the Secretary-General of the United Nations, succeeding Ban Ki-moon.

Croatia assumes the presidency of the Council of the European Union for the first time.

The United Kingdom officially completed its transition out of the European Union, marking the end of the Brexit process.

Croatia adopts the euro as its official currency and joins the Schengen Area, marking significant milestones in its European integration.