Read about history and pick out a good one!

https://en.wikipedia.org/wiki/August_15

1971 – President Richard Nixon completes the break from the gold standard by ending convertibility of the United States dollar into gold by foreign investors.

1977 – The Big Ear, a radio telescope operated by Ohio State University as part of the SETI project, receives a radio signal from deep space; the event is named the "Wow! signal" from the notation made by a volunteer on the project.