by the North Central Association of Schools and Colleges in 1913. Statehood: 1907–1915 Kendall College, a Presbyterian school, moved to Tulsa from Muskogee in 1907. This school, the forerunner of the University of Tulsa, became the start of higher education in Tulsa. By the time Oklahoma achieved statehood in 1907, Tulsa had a population of 7,298. According to the 1910 U. S. census, the population of Tulsa had increased to 18,182. The first petroleum refinery in Tulsa, built by Texaco, went onstream in 1910 in West Tulsa, across the Arkansas River from Tulsa. Texaco continued to operate the plant until 1983, when the facility was sold to Sinclair Oil Company. At the time the refinery was sold to Sinclair, the refinery capacity was rated at per day. The second refinery was built in West Tulsa two miles (3 km) upstream on the Arkansas River in 1913 by Joshua Cosden, who also founded the Cosden Petroleum Company. The refinery later operated as the Sunray D-X and Sunoco' brands. Holly Corporation of Dallas, Texas bought both the former Texaco and Sunoco refineries in 2009 and announced that it would operate both as a single refinery. High rise buildings began to appear downtown during this decade. The Tulsa Hotel and the Brady Hotel annex were both constructed around 1910. The 16-story Cosden Building was constructed in 1918, and is considered the first skyscraper in Tulsa. It was later acquired by Mid Continent Oil Company, who built an adjacent tower integrated with the older structure. This is now called the Mid-Continent Tower. 1917 saw the construction of the Federal Building that contained both the main post office and courtrooms of United States District Court for the Eastern District of Oklahoma. The building was substantially expanded in 1933, covering the west side of Boulder Avenue between Second and Third Streets. Second oil boom: 1915–1930 By 1920 the population boomed to over 72,000. Many of these new residents came from Pennsylvania, Ohio, and New York. The second surge of oil discoveries occurred between 1915 and 1930, and firmly established Tulsa as the "Oil Capital of the World". Wealthy oilmen such as Waite Phillips, William G. Skelly and J. Paul Getty built stately mansions and beautiful modern headquarters. The prevalence of the Art Deco style of architecture during this period resulted in a treasure trove of beautiful structures. Cultural institutions such as a Symphony and professional Ballet