When “The Wizard of Oz” first hit theaters in August 1939, flying monkeys were the least of America’s worries.

The Depression, already almost a decade long, continued to grind away, and Germany stood on the verge of invading Poland, igniting a global conflagration that would envelop the United States just two years later.

Moviegoers needed escape. And along came Judy Garland’s Dorothy Gale, a Kansas farm girl whose ruby slippers stepped out of the dreary present and into a Technicolor future, a magical Oz populated by talking scarecrows, Munchkins, bubble-riding witches and a con man of a wizard who showed that all we ever needed was within ourselves.

Hard as it is to believe, the Judy Garland-starring fantasy classic “The Wizard of Oz” is 70 years old, and to mark the event, a special one-night-only theatrical presentation of the film in newfangled high-definition is set for 7 p.m. Wednesday in theaters nationwide, including more than 20 in Southern California.