In the decades after the Civil War, libraries were scarce in much of the United States. Many towns had no library at all, and those libraries that did exist were typically small and private, run by clubs or lodges that had scraped together collections of books to lend to their members or, on occasion, to outsiders who paid a fee for borrowing privileges. For the most part, towns did not have library buildings; book collections were housed instead in cheap offices or in unused space in public buildings. Even in bigger cities, it was often difficult to borrow books. Until the very end of the 19th century, Pittsburgh, for instance, had just one private lending library, and it struggled to stay afloat. And few people, if any, took seriously the idea that every town in the country should have a public library where citizens would have free and equal access to books.

Andrew Carnegie changed all that. Carnegie was an embodiment of the American Dream; born poor in Scotland, he had emigrated to the United States and built a fortune in the steel industry, turning himself into one of the country's wealthiest and most powerful businessmen. As Carnegie told it, when he was a young boy, he'd had to work instead of going to school. But a wealthy local man named Colonel Anderson had put together a small library of about 400 books, and every Saturday, Carnegie was allowed to read and borrow some of them. The experience, Carnegie wrote later, convinced him that there was no more productive way to help children develop than to build public libraries. And so, beginning in the 1880s, he set out to do just that, in towns all across the country.