When oil was discovered in Corsicana, Texas, in 1894, local developers invited Cullinan to Texas to advise them on production and marketing techniques. In Corsicana he organized the J. S. Cullinan Company, which later became Magnolia Petroleum Company. Among the contributions that Cullinan made to the Corsicana oil industry were the introduction of oil as a fuel for locomotives, the use of natural gas for lighting and heating, and the utilization of oil to settle dust on the city's streets. South of Corsicana, Cullinan constructed a refinery that began operation in 1899 and was the first such facility west of the Mississippi. In addition, in 1899 he was instrumental in persuading the Texas legislature to enact the state's first petroleum-conservation statute.
Cullinan moved his operations to Beaumont shortly after the Spindletop discovery in 1901. There he founded the Texas Company (later Texaco) in 1902; he served as company president until he lost control of the stock in a proxy fight with eastern investors in 1913. When he moved his operations and the Texaco headquarters to Houston in 1905, Cullinan established that city as the focal point of the oil industry in the Southwest. He remained active in the industry after his resignation as president of Texaco. Eventually he founded ten companies involved in the exploration, production, refining, and marketing of Texas petroleum, and he was instrumental in developing oil deposits in the Sour Lake, Humble, and East Texas oilfields.
Cullinan served as president of the Houston Chamber of Commerce from 1913 until 1919 and supported development of the Houston Ship Channel. He also constructed the North Side Belt Railway around the city in 1922. During World War I he was special advisor to the Food Administration under Herbert Hoover. He was a patron of the Museum of Fine Arts, the Houston Symphony Orchestra, and Houston Negro Hospital. From 1928 to 1933 he was chairman of the Mount Rushmore National Memorial Committee. He married Lucy Halm on April 14, 1891; they had five children. Cullinan died of pneumonia while visiting his friend Herbert Hoover in Palo Alto, California, on March 11, 1937.
29° 45.736, -095° 23.224
Little Hillside Section