1565: Portuguese soldier Estácio de Sá founds the city of Rio de Janeiro, Brazil

1642: Georgeana (York) in Maine becomes the first incorporated American city

1780: Pennsylvania becomes first US state to abolish slavery (for newborns only)

1847: Michigan becomes the first English-speaking jurisdiction to abolish the death penalty (except for treason against the state)

1869: US postage stamps featuring scenes are issued for the first time, depicting a post horse and rider, a locomotive, a shield, an eagle, and a ship, the Adriatic

1872: Yellowstone becomes the world’s first national park

1954: US explodes Castle Bravo, a 15-megaton hydrogen bomb at Bikini Atoll, which accidentally becomes the most powerful nuclear device ever detonated by the US

Source: Onthisday.com