On April 14, 1798, the cornerstone was laid for Main Building (now known as South Building). The structure, however, was not completed until 1814.
The animated .gif above was created from a stereograph of South Building (and Playmaker’s Theater, then known as Smith Hall) taken from Cameron Avenue some time between 1870 and 1904. You can view the original stereograph here (from the North Carolina Collection Photographic Archives; P43: Stereograph Collection; image no. 43.68.5; negative no. 77-227).