A Tar Heel is a nickname applied to the U.S. state of North Carolina and its people, as well as the nickname of the University of North Carolina athletic teams, students, alumni, and fans. The origins of the Tar Heel nickname trace back to North Carolinas prominence from the mid-18th through the 19th century as a producer of turpentine, tar, pitch, and other materials from the states plentiful pine trees. "Tar Heel" (and a related version, "Rosin Heel") was often applied to the Poor White laborers who worked to produce tar, pitch, and turpentine. The vast production of tar from North Carolina led many, including Walt Whitman, to give the derisive nickname of "Tarboilers" to the residents of North Carolina. North Carolina was nicknamed the "Tar and Turpentine State" because of this industry. These terms evolved until the nickname "Tar Heel" was being used to refer to residents of North Carolina. The term gained prominence during the American Civil War, when it had a mainly pejorative meaning. However, during the Civil War, North Carolina soldiers flipped the meaning of the term and turned an epithet into an accolade. They called themselves "tar heels" as an expression of state pride. Others adopted the term, and North Carolina became widely known as the "Tar Heel State".