The history of Houston begins almost exactly at the same time as Texas Independence. The Texas Revolution, which resulted in Texas' independence from Mexico and established the Republic of Texas, began with a rebellion in 1835 that led to the disaster of the Alamo and the ultimate victory at San Jacinto in the spring of 1836. In August 1836, two New York real estate promoters, J.K. and A.C. Allen, purchased 6,642 acres of unimproved land for $9,428. Located at the upper end of tidewater on Buffalo Bayou, the site was, in the words of the promoters, designated by Nature as the "place for the future seat of government." To further this ambition, they named their future city after the hero of the revolution, Sam Houston. Houston was indeed named the capital, well before it was ready to host any government functions. At the time that Sam Houston arrived in January 1837, he found only one log cabin and a dozen people. However, the town soon boomed and its population had soared into the hundreds within a few months. The swampy environs of Houston, which resulted in many deaths from yellow fever, as well as widespread lawlessness, contributed to the Republic's decision to move its capital to Austin in late 1839. By 1840, the move had been officially completed. In 1846, Texas was admitted to the Union. When the first decennial census was taken in 1850, Houston reported a population of 2,397. Galveston, Texas, just southeast of Houston on the Gulf coast, remained the largest city in the state. The first steamship reached Houston in 1837 and the first railroad began operations in 1853. At the outset of the Civil War, the local population supported secession. Actual military action came no closer than Galveston. Texas was readmitted to the Union in 1870 and Houston reported a population of 17,735, making it the second largest in the state. Houston's commercial development received a boost when Congress designated it a port in 1870. A bill in 1872 appropriated funds to develop the ship canal. Technological progress also was evident when the first telephone exchange was organized in 1880, and the first electric power plant was built a few years later. The great hurricane that swept over Galveston in 1900 made clear the advantages of Houston's location farther inland. Following the discovery of oil at Spindletop in 1901 and other strikes in the area, Houston became the financial and supply center for the Texas petroleum industry. Houston's expansion continued almost unabated throughout the 20th century. Following World War II, the Port of Houston became the country's second most active port in terms of tonnage. Annexation of adjacent land in 1948 expanded the area of the city to 216 square miles. NASA's Manned Spacecraft Center moved to Houston in 1962. At the end of the century, Houston ranked as the fourth largest city in America.