Amazing changes took place in the United States between the first federal census in 1790 and the eleventh in 1890. At the end of the eighteenth century, the United States was a struggling nation composed of mutually wary political communities stretched along the Atlantic seaboard. Transportation and communication were primitive, and the American economy revolved around agriculture and the simple commercial networks that got farm products to market. More than 90 percent of the citizens lived in the countryside, and the nation's largest city, Philadelphia, had only 42,444 inhabitants.…