Amid rapid change, the United States remained a deeply religious nation. But new discoveries enhanced another kind of belief: faith in science. In the early nineteenth century, most Americans had believed the world was about six thousand years old. No one knew what lay beyond the solar system. By the 1910s, paleontologists were classifying the dinosaurs, astronomers had identified distant galaxies, and physicists could measure the speed of light. Many scientists and ordinary Americans accepted the theory of evolution.

Scientific discoveries received widespread publicity through a series of great world’s fairs, most famously Chicago’s 1893 World’s Columbian Exposition, held (a year late) to celebrate Columbus’s arrival in America in 1492. At the vast fairgrounds, visitors strolled through enormous buildings that displayed the latest inventions in industry, machinery, and transportation. They marveled over a moving sidewalk and, at dusk, saw the fair buildings illuminated with strings of electric lights. One observer called the fair “a vast and wonderful university of the arts and sciences.”

It is hardly surprising, amid these achievements, that “fact worship” became a central feature of intellectual life. Researchers in many fields argued that one could rely only on hard facts to understand the “laws of life.” In their enthusiasm, some economists and sociologists rejected all social reform as sentimental. Fiction writers and artists kept a more humane emphasis, but they made use of similar methods — close observation and attention to real-life experience — to create works of realism. Other Americans struggled to reconcile scientific discoveries with their religious faith.