this comes up every year or so, but this year is special
The Day the Earth Stood Still?
Don’t know if this is what you’re looking for, but April 1 1954 was
the premiere of the first Godzilla movie in Japan
mmm
Both good guesses and may both be accurate as to timing (I don’t know about either one) but not the one I’m looking for. Think much more trivial and arcane – unless you rank this movie as highly as I do. 
A car wreck on Kingston Pike, west of Knoxville, Tennessee?
Not according to IMDB.
But that would be a huge movie event in my book.
First 3-D movie?
The winner! Nice work!
http://www.lyricsmode.com/lyrics/r/robert_mitchum/the_ballad_of_thunder_road.htmlMy cite was Wikipedia, but it turns out I read it wrong.
Never mind
mmm
Awesome! Thanks for sharing.
One year anniversary bump! 
They sent 200 agents just to try to stop one guy? They must have had one hell of a budget.
Not to mention effectiveness! 