Taishanese people, Sze Yup people, or Toisanese (, Taishanese: Hlei Yip Gong Ong Ngin) are a Han Chinese group coming from Sze Yup (四邑), which consisted of the four county-level cities of Taishan, Kaiping, Xinhui and Enping. Heshan has since been added to this historic region and the prefecture-level city of Jiangmen administers all five of these county-level cities, which are sometimes informally called Ng Yap. The ancestors of Taishanese people are said to have arrived from central China under a thousand years ago and migrated into Guangdong during the Tang Dynasty. Taishanese, as a dialect of Yue Chinese, has linguistically preserved many characteristics of Middle Chinese. The Taishanese are part of the Yue Chinese family and have an identity that distinguishes themselves from the dominant Cantonese people. Among the Han Chinese, Taishanese are a source for many famous international Chinese celebrities and have produced the largest numbers of Chinese actors and singers of any region in mainland China. Despite their small population, Taishanese people have also produced a number of famous academics and historical figures. Sze Yup or Jiangmen is considered the home of Chinese Academicians, a title gifted by the world's largest research institution, the Chinese Academy of Sciences. The total of academicians is 31 people, a city with over 20 is considered extremely rare in China. Among Asian Americans, Taishanese are influential in politics and were the first Americans of Asian descent to be elected as governors (for example Gary Locke), mayors and congressmen. The Taishanese were the first Chinese people to settle in America and the Taishanese language was the original lingua franca of Chinatowns. Taishanese as the lingua franca was later replaced with Cantonese after being overwhelmed by immigration from Guangzhou and its satellite cities when the Chinese Exclusion Act was fully repealed under the Immigration and Nationality Act of 1965. Taishanese American laundrymen and shopkeepers were a primary source of funding that helped launch Dr.