Drive-ins were slow to catch on. In 1940, only 18 were open nationally. As World War II drew to a close, they began to spring up across the country. In 1948, there were 820 theaters. By the end of the 1940s drive-ins were more popular than indoor theaters, partly due to the invention of an in-car speaker.

The baby boom of the 1950s further increased the popularity of drive-ins. Many owners built playgrounds to make their theaters more attractive to families. From 1948 to 1958, about 3,200 new drive-ins were built.

Through the 1960s, the number of theaters stayed about the same. Their numbers began to decline in the 1970s due to rising property values. The land used for drive-ins could be used more profitably for other things. Also, drive-ins often showed "B" movies, which were less popular.

By the 1980s, families had cable television and videocassettes to watch movies at home, further hurting the drive-ins. By 2003, the number of drive-ins had sunk to 432.

Next: New Jersey Drive-In Theaters