C. Camden, NJ in 1933
The first-ever true "drive-in" movie theater, the Camden Drive-In, opened on June 6, 1933 in Camden, New Jersey. Before that, there were attempts at opening "outdoor theaters" but those were done in temporary locations such as downtown streets. Located on Admiral Wilson Boulevard, the idea for a "drive-in" as it later came to be called was the brainchild of Richard Hollingshead. Richard Hollingshead was a movie fan with a connection to the automotive world as he worked at his father's automotive company which was called Whiz Auto Products in Camden. Reportedly inspired by his mother’s struggle to sit comfortably in traditional movie theater seats, Hollingshead came up with the idea of an "open-air theater" where patrons watched movies in the comfort of their own automobiles.
He began experimenting with showing movies in his driveway of his home. He obtained a movie projector which he placed on the hood of his car. He tied a movie screen to some trees and put a radio behind the screen for sound. He tried several setup variations before he found what he thought was the right configuration of projector, screen, sound and spacing between cars. And with that he applied for a patent for a drive-in theater in 1932 which was granted in May of 1933. Shortly after in June 1933, he opened his first drive-in which was originally called the Automobile Movie Theatre.
His slogan for his drive-in theater? "The whole family is welcome, regardless of how noisy the children are."
source: History Channel