The first two decades of the 20th century brought tremendous changes on both sides of the Atlantic. People zipped around in automobiles, airplanes, and motorcycles. The rise of women's skirt lengths threw men's heads in a tizzy along with the matrons of society who wanted to cling to the Victorian age. And along the way, young ladies stepped out with a beau--alone, without a chaperone--leaving parents and guardians sitting on tenterhooks until their daughters returned.
Eff Sep 8th, you'll see the change as shown in this graphic: