https://www.mlb.com/news/ted-williams-faced-defensive-shifts-in-1940s-c191605204

>This wasn't actually the first recorded instance of the shift. In the 1920s, some managers moved their defenses around to the right side against another dead pull left-handed batter, the Phillies' Cy Williams, according to a Society For American Baseball Research (SABR) profile. This Williams, who batted .320 from 1920-26, reportedly admitted, "I couldn't hit a ball to left if my life depended on it."

It wasn't used anywhere near as frequently back then, but the shift actually has been around for just about a hundred years.