Fifty-year-old John Gadsby is alarmed by the decline of his hometown, Branton Hills, and rallies the city's young people to form an "Organization of Youth" to build civic spirit and improve living standards. Gadsby and his youthful army, despite some opposition, transform Branton Hills from a stagnant municipality into a bustling, thriving city. Toward the end of the book the members of Gadsby's organization receive diplomas in honor of their work. Gadsby becomes mayor and helps increase Branton Hills' population from 2,000 to 60,000. The story begins around 1906 and continues through World War I, Prohibition, and President Warren G. Harding's administration.