Cornelius Ennis, mayor of Houston, merchant, Confederate blockade runner, and railroad entrepreneur, was born on September 26, 1813, in Belleville, New Jersey. His father's family had come to New Jersey from Ireland in the latter part of the seventeenth century, and his mother was a descendant of the Doremus family, who were among the first settlers from Holland. After receiving a liberal education in New Jersey Ennis went in 1834 to New York City, where he worked in a drugstore. He moved to Houston, Texas, and opened a drugstore in 1839. After George W. Kimball became a partner, Ennis expanded into general merchandising. They sent the first shipment of cotton from Galveston to Boston in 1841.
His success in business allowed Ennis to marry Jeannette Ingals Kimball, his partner's sister, in 1841; they had four children. Ennis and his wife supported Christ Episcopal Church.
In 1842 Kimball sailed to New York with cotton and partnership funds to be invested, and was drowned with his family in a storm off the Florida coast. This serious setback did not hinder Ennis's cotton-export business for long. Realizing that improved transportation was necessary for expansion, he turned to railroads. He was an incorporator of the Houston and Texas Central Railway, which began in 1853; along with Paul Bremond, William M. Rice, Thomas W. House, William R. Baker, and William J. Hutchins, Ennis served on the board of directors for many years. He was also the railroad's general superintendent and comptroller. For several years he had offices in New York, where he obtained loans and purchased supplies to complete the road. Ennis, Texas, an early terminus of the road, was named in his honor.
As mayor of Houston from July 1856 to December 1857, Ennis supervised the completion of the city-owned Houston Tap Railroad, begun in April 1856. This tap into the Buffalo Bayou, Brazos and Colorado Railway preserved the Brazos cotton trade with Houston. After the city sold the tap road in 1858, the new owners renamed it the Houston Tap and Brazoria. Ennis served on the board of directors of HT&B, which brought the first carload of sugar and molasses to Houston in 1859. He also succeeded in having arrested and sent to the penitentiary a band of robbers who had preyed for years on shippers and teamsters going to Houston.
During the Civil War Ennis ran cotton through the Union blockade to Havana, Cuba, then to England via Mexico. At his own expense he purchased an ironclad steamer, the Jeannette, for $40,000 in gold. He used the ship to carry the rifles, gunpowder, percussion caps, clothing, and other equipment he bought in Havana for the Confederate government. His successful blockade running enabled him to expand his cotton-export business after the war, when he opened a branch office in Galveston with Frank Cargill and N. Anderson. He also invested heavily in the Galveston News and the Dallas News (see DALLAS MORNING NEWS). Alfred H. Belo, president of the News, married Ennis's oldest daughter, and Cargill married the second daughter. The youngest daughter married Cesar Lombardi, a Houston merchant and later president of the Dallas News.
Ennis also continued his interest in railways. The Houston Tap and Brazoria was sold to Houston businessmen in 1870, and three years later it was taken over by the International-Great Northern. Throughout these changes Ennis continued to serve on the board of directors. He promoted the Houston Ship Channel, street railways, and public utilities of all kinds. He lived in Houston sixty years and died on February 13, 1899, in his home. He was interred at Glenwood Cemetery in Houston.