From the back of the book:

Designers & Dragons: The '70s is a comprehensive picture of the beginnings of the RPG industry. This second edition expands the original single book into a series of four, and we've added over 50,000 new words to this volume alone. Learn about the colorful history of TSR and the wave of D&D inspired games (and gaming companies) to follow, and dip your toes into wargaming trivia. Regardless of your gaming background, Shannon Appelcline's meticulously researched history won't disappoint.