In October 1869, as America stood on the brink of becoming a thoroughly modern nation, workers unearthed what appeared to be a petrified ten-foot giant on a remote farm in upstate New York. The discovery caused a sensation. Over the next several months, newspapers devoted daily headlines to the story and tens of thousands of Americans--including Oliver Wendell Holmes, Ralph Waldo Emerson, and the great showman P. T. Barnum--flocked to see the giant on exhibition. In the colossus, many saw evidence that their continent, and the tiny hamlet of Cardiff, had ties to Biblical history. American science also weighed in on the discovery; and in doing so revealed its own growing pains, including the shortcomings of traditional education, the weaknesses of archaeological methodology, as well as the vexing presence of amateurs and charlatans within its ranks. A national debate ensued over the giant's origins, and was played out in the daily press. Ultimately, the discovery proved to be an elaborate hoax. Still, the story of the Cardiff Giant reveals many things about America in the post-Civil War years. After four years of destruction on an unimagined scale, Americans had increasingly turned their attention to the renewal of progress. But the story of the Cardiff Giant seemed to shed light on a complicated, mysterious past, and for a time scientists, clergymen, newspaper editors, and ordinary Americans struggled to make sense of it. Hucksters, of course, did their best to take advantage of it. The Cardiff Giant was one of the leading questions of the day, and how citizens answered it said much about Americans in 1869 as well as about America more generally.