1. On December 12, 1785, a petition signed by 719 New Yorkers was sent to the Continental Congress urging them to end slavery. This petition is believed to be one of the first abolitionist petitions in U.S. history.

2. In 1893, the New York Society for the Prevention of Cruelty to Children was founded on December 12. It was the first organization of its kind in the world and served as a model for others around the globe.

3. On December 12, 1912, construction began on the Woolworth Building in lower Manhattan. At the time, it was the tallest skyscraper in the world and remained so until 1930.

4. The first hospital for children in New York City, now known as Children's Hospital at Montefiore, opened its doors on December 12, 1915. It was established to provide medical care to underprivileged children in the Bronx.

5. On December 12, 1972, the United Nations General Assembly adopted the Treaty on the Prohibition of the Emplacement of Nuclear Weapons and Other Weapons of Mass Destruction on the Seabed and the Ocean Floor and in the Subsoil Thereof. The treaty aimed to prevent the proliferation of nuclear weapons and other weapons of mass destruction in the ocean.