As a nomadic cultural historian, my subjects have led me in wildly different directions. I spent every Friday for five years in a dim, dusty reading room in West Orange, New Jersey, formerly a laboratory on the second floor of Thomas Edison’s headquarters, deciphering the blunt-penciled scrawls of the celebrated inventor. Two years after my biography of Edison appeared, I found myself laboring up vertiginous stairs at daybreak in Mexico, photographing the faded ocher outlines of winged snakes etched into stone temples at the vast ruins of Teotihuacán. The daunting treks led to a book on Mesoamerican myth, Legends of the Plumed Serpent.

Those two disparate worlds somehow collided unexpectedly on a recent afternoon in the hushed, temperature-controlled precincts of the National Museum of the American Indian storage facility in Suitland, Maryland. There, staffers pushing a rolling cart ushered one of the museum’s greatest treasures into the high-ceilinged room. Nestled in an acid-free corrugated cardboard container was the earliest known example of telephone technology in the Western Hemisphere, evoking a lost civilization—and the anonymous ancient techie who dreamed it up.