Plano had been settled in the early 1840s by European people. It was named as a reference to the local terrain, unvaried and devoid of any trees. The name Plano comes from the Spanish word for "flat" and it was accepted by the post office in 1852. The completion of the Houston and Central Texas Railway helped the city to grow in 1872 and in 1873, Plano was incorporated. The public school system was organized in 1891. The city is situated approximately 20 miles (32.2 km) north of downtown Dallas, specifically, on U.S. Highway 75 fifteen miles north of Dallas in southwestern Collin County. The city of Plano is also a part of the Dallas-Fort Worth metropolitan area. Plano lies mostly within Collin County but includes a small portion that extends into Denton County. The city is also a hub for many corporate headquarters and was also considered to be the safest city in the nation by Forbes in 2011. It has a total area of 71.6 square miles and the population was 286,143 in 2017. Also, Plano, along with Houston, has one of the state's two major concentrations of Chinese Americans.