What was the first Choose Your Own Adventure book?

The first official Choose Your Own Adventure book was 'The Cave of Time' by Edward Packard, published by Bantam Books in 1979 as the launch title of the numbered series. Packard had written an earlier branching story, 'Sugarcane Island', in the mid-1970s, which is often credited as the concept's origin, but 'The Cave of Time' kicked off the famous line that sold millions of copies through the 1980s. Each book put the reader in the second person ('you') and ended sections with choices that jumped to different pages. The series popularized the whole idea of interactive, branching storybooks for young readers. That format still inspires digital story tools today, including browser builders that handle the branching for you.