Nathaniel C. Lewis, merchant and legislator, was born in Falmouth, Massachusetts, on June 11, 1806, the son of Nathaniel and Sarah (Hatch) Lewis. He went to sea at age fourteen in a whaling vessel. Accounts of his early life and journey to Texas are confused and contradictory. According to family legend he was shipwrecked on the coast of South America and taken to New Orleans and thence to Port Lavaca. Another story has him settling in Cincinnati, then proceeding to Texas on a boatload of tobacco that was seized by Mexican authorities. According to this account he was befriended by Castillo de la Garza, who took him to San Antonio in 1830. He entered the mercantile trade, first at Indianola and shortly thereafter in San Antonio. By 1832 he is said to have been involved in coastal trade. As a founder of the firm of Lewis and Groesbeck on Main Plaza in San Antonio, he became one of the leading merchants in the Southwest before the Civil War. He also established a gristmill, was an early real estate promoter and developer, and was the first large-scale cattleman in the region. He owned herds from the Medina River to the coast.
When Santa Anna's forces entered San Antonio on February 23, 1836, Lewis fled to Gonzales, although he is reputed to have supplied the Alamo garrison from his store and was perhaps the last man to have left the mission before the battle of the Alamo on March 6. He is said to have served as a scout for Houston's army. After the battle of San Jacinto he returned to San Antonio to reestablish his mercantile business. In 1839 he was elected to the House of Representatives of the Fourth Congress of the Republic of Texas from Bexar County. After 1840 he served several terms as alderman in San Antonio and once served as mayor pro tem. During the 1850s he was engaged in the freighting business between San Antonio and El Paso. Lewis was married twice, first to Letitia Groesbeck, then to Mary Fanny Liffering, with whom he had two children. He died in San Antonio on October 21, 1872. His brother, Henry M. Lewis, was a San Antonio attorney and editor of the West Texan.