Sister cities of Dallas

Dallas /ˈdæləs/ is the ninth-largest city in the United States and the third-largest city in the state of Texas. The bulk of the city is in Dallas County, of which it is the county seat. However, slices of the city are located in Collin, Denton, Kaufman, and Rockwall counties. The city had a population of 1,197,816 in 2010, according to the United States Census Bureau.

The city is the largest economic center of the 12-county region. Dallas–Fort Worth–Arlington metropolitan area had a population of 6,645,678 in 2012. The metroplex economy is the sixth largest in the United States, with a 2010 gross metropolitan product of $374 billion. Its 2010 Real GDP amounted to $325 billion.

Dallas was founded in 1841 and formally incorporated as a city in February 1856. The city's economy is primarily based on banking, commerce, telecommunications, computer technology, energy, healthcare and medical research, transportation and logistics. The city is home to the third largest concentration of Fortune 500 companies in the nation. Located in North Texas, Dallas is the main core of the largest inland metropolitan area in the United States that lacks any navigable link to the sea.

The city's prominence arose from its historical importance as a center for the oil and cotton industries, and its position along numerous railroad lines. With the advent of the interstate highway system in the 1950s and 1960s, Dallas became an east/west and north/south focal point of the interstate system with the convergence of four major interstate highways in the city, along with a fifth interstate loop around the city. Dallas developed a strong industrial and financial sector, and a major inland port, due largely to the presence of Dallas/Fort Worth International Airport, one of the largest and busiest airports in the world.

In the latest rankings released on September 14, 2011, Dallas was rated as an Alpha- world city by the Globalization and World Cities Study Group & Network and is the only city in the South Central region to achieve that status. Dallas is also ranked 14th in world rankings of GDP by the Organization for Economic Co-operation and Development.