Princeton is at the intersections of U.S. Highway 380 and Farm roads 75, 1377, and 982, seven miles east of McKinney in east central Collin County. In the late 1870s T. B. Wilson and his brother George began farming near the site of future Princeton. In 1881 the Missouri, Kansas and Texas Railroad Company extended its line from Greenville to McKinney, passing through land owned by the brothers. The name Wilson's Switch was commonly used to designate the area. When residents applied for a post office branch, however, they learned that the name Wilson was already being used. The community then submitted the name Princeton in honor of Prince Dowlin, a landowner and promoter of the town. This name was accepted, and a post office was established in 1888. Located in the rich agricultural region of the Blackland Prairie, Princeton quickly became a retail and commercial center for area farmers. In addition to providing mills and grain elevators for wheat, corn, onions, and sorghums, the town also housed a lumber factory that became the state's largest producer of bois d'arc lumber. By the mid-1920s the town provided electricity, water, natural gas, and paved roads for 500 residents. It also had more than twenty-five businesses, including a bank and a weekly newspaper. During World War II Princeton was one of 120 Texas towns to house a camp for prisoners of war. The city employed the prisoners to make improvements, including enlarging the public park. Following the war the town's population remained 564 until the completion in 1953 of Lake Lavon, five miles away. The proximity of the lake helped raise the population to 1,100 by 1972. The growth of the Dallas metropolitan area and the emergence of nearby Plano as the business center for Collin County caused the population of Princeton to increase to 3,408 by 1982. By 1988 more than thirty businesses were located in the town, which was surrounded by horse and cattle ranches and productive farms. Princeton is known as an onion-growing center. In 1990 the population was 2,321. The population was 3,477 in 2000.