July 17th
In 1821, Florida is ceded to the U.S. by Spain.
In 1867, the first dentistry school associated with a university is founded by Harvard in Boston, MA.
In 1902, the air conditioner is created by Willis Carrier in Buffalo, NY.
In 1938, Douglas "Wrong Way" Corrigan takes off from Brooklyn, NY with a flight plan destined for California. He ends up in Ireland. Despite denials by Corrigan, many believe it was intentional.
In 1941, Joe DiMaggio's record hitting streak comes to an end.
In 1944, two ships laden with ammunition for the war explode in Port Chicago, CA, killing 320.
Port Chicago disaster - Wikipedia
In 1945, President Harry Truman meets with Winston Churchill and Joseph Stalin in Potsdam, Germany to decide Germany's future.
In 1955, Disneyland in Anaheim, CA is dedicated and opened by Walt Disney.
In 1955, Arco, Idaho becomes the first U.S. city lit by nuclear power.
In 1967, a race riot erupts in Cairo, IL.
Racial unrest in Cairo, Illinois - Wikipedia
In 1975, an Apollo spacecraft successfully docks with a Russian Soyuz spacecraft in orbit becoming the first link up between the two nations in space.
In 1984, the national drinking age is changed from 18 to 21.
In 1989, the first flight of the B-2 Spirit Stealth Bomber occurs.
In 1996, TWA Flight 800 bound for Paris explodes off the coast of Long Island, NY, killing all 230 on board.
In 2014, Eric Garner dies after being placed in a chokehold by the NYPD.
https://www.history.com/this-day-in-history/eric-garner-dies-nypd-chokehold