Spain legalized same-sex marriage.
This made Spain the fourth country in the world to do so.
Source
The Nazi Party killed around 1,000 people, which became known as the 'Night of Long Knives.'
The US government passed the Indian Trade and Intercourse Act.
Donald Trump became the first US president to visit North Korea while meeting Kim Jong Un.
The first leap second was added to the UTC time system.
The first Chevrolet Corvette was manufactured in the US.
