July 7, 1947
Roswell, New Mexico
A flying saucer is discovered on a ranch
(Sources vary as to which exact day the disc was found, citing the 6th through the 8th.)
The craft was officially recognized as a weather balloon by the United States military, though allegedly the device was made for the purpose of nuclear test monitoring which the government decided to conceal from the public. The incident was quickly forgotten about until the 1970s when conspiracy theorists and UFO researchers brought the crash back into the public eye, though the research is largely considered unreliable.