PHOTO: North Carolina Museum of Natural Sciences

Almost 40 years after the Civil War ended, North Carolina was still reeling from the conflict. To alleviate the long-lasting damage, the Tar Heel State used exhibitions to attract immigrants. At the 1906 Boston Food Fair shown here, the North Carolina Department of Agriculture touted its textiles, agriculture, and natural history, employing several 12-inch-diameter granite "bowling balls" as a traffic builder. The polished spheres were meant, in part, to counter the conventional wisdom that the igneous rock, popularly used for paving stones and building veneers, was only available in New England.