Read em and pick one if you want.
https://en.wikipedia.org/wiki/April_30
1803 – Louisiana Purchase: The United States purchases the Louisiana Territory from France for $15 million, more than doubling the size of the young nation.
https://en.wikipedia.org/wiki/Louisiana_Purchase
The Louisiana territory included land from fifteen present U.S. states and two Canadian provinces. The territory contained land that forms Arkansas, Missouri, Iowa, Oklahoma, Kansas, and Nebraska; the portion of Minnesota west of the Mississippi River; a large portion of North Dakota; a large portion of South Dakota; the northeastern section of New Mexico; the northern portion of Texas; the area of Montana, Wyoming, and Colorado east of the Continental Divide; Louisiana west of the Mississippi River (plus New Orleans); and small portions of land within the present Canadian provinces of Alberta and Saskatchewan. Its non-native population was around 60,000 inhabitants, of whom half were African slaves.[2]
| Louisiana Purchase Vente de la Louisiane | |||||
| Expansion of the United States | |||||
| |||||
 The modern United States, with Louisiana Purchase overlay | |||||
| History | |||||
| • | Established | July 4, 1803 | |||
| • | |||||
1939 – The 1939-40 New York World's Fair opens.
"The 1939–40 New York World's Fair, which covered the 1,216 acres (492 ha) of Flushing Meadows–Corona Park (also the location of the 1964–1965 New York World's Fair), was the second most expensive American world's fair of all time, exceeded only by St. Louis's Louisiana Purchase Exposition of 1904. Many countries around the world participated in it, and over 44 million people attended its exhibits in two seasons. It was the first exposition to be based on the future, with an opening slogan of "Dawn of a New Day", and it allowed all visitors to take a look at "the world of tomorrow"."
As a child, I was in awe of the Fair ... the giant symbols of the Fair called the Trylon and Perisphere, the Parachute Jump (later moved to Coney Island), the GE exhibit displaying a kitchen with all the latest appliances, and exhibits from many other countries.
