What happened in Roswell 1947?

I have to agree with Petrusclavus. To expand upon the answer given however, the U.S.A actually helped fund the popularised alien U.F.O. myth during the Cold War era. In response the Soviet Union opened the largest U.F.O. study files in existence. Why did the U.S. fund this? To cover up new military aircraft... I don't believe in alien U.F.O's and I certainly do not believe in the autopsy.