Night games transformed the business of professional baseball, as the smaller, demographically narrower audiences able to attend daytime games gave way to larger, more diversified crowds of nighttime spectators. Many ball club owners were initially conflicted about artificial lighting and later resisted expanding the number of night games during the sport's existential struggle to balance ballpark attendance and television viewership in the 1950s. This first-ever comprehensive history of night baseball examines the factors, obstacles and trends that shaped this dramatic change in both the minor and major leagues between 1930 and 1990.