This Grand Opening ad from The Daily News of Huntingdon PA, May 17, 1950, establishes the opening date of the Midway Drive-In. The Midway ran a similar ad a couple of days earlier promoting the opener.
I have no interest in the copyright for this ad. It’s very likely that it’s in the public domain now, but don’t take my word for it. I uploaded it here in the scholarly fair use of fixing the Midway’s opening date.
No one has favorited this photo yet