With the Sabine Pass Ship Channel, the Sabine-Neches Waterway forms a Y-shaped set of interlocking river channels and canals extending from the Gulf of Mexico to Port Arthur, Beaumont, and Orange, Texas. The Consultation of 1835 designated the mouth of the Sabine River a port; a customhouse was built there three years later. Union forces unsuccessfully attempted to use the Sabine and Neches rivers to threaten Southeast Texas during the Civil War, but their effort was thwarted at the battle of Sabine Pass. Extensive construction to improve the waterways began with river and harbor acts of 1875, 1882, and 1896, when the mouth of the channel was deepened and jetties were built to prevent silting. Some improvements in the Sabine and Neches rivers were authorized in 1878, and the Port Arthur Canal and Dock Company began building a more suitable channel to Port Arthur in 1895. Legal entanglements necessitated the use of private funds to dredge the Port Arthur Canal west of Sabine Lake; the canal opened in 1899. The discovery of the Spindletop oilfield in 1901 increased demand for deep-water navigation along the lower Sabine and Neches rivers. With the support of Congressman Samuel Bronson Cooper and future governor William P. Hobby, Congress appropriated funds for extending the channel. Despite unfavorable reports by engineers, a twenty-five-foot-deep channel was completed to Beaumont in 1916. Additional dredging and improvements extended the waterway to Orange. By 1972 the Sabine-Neches Waterway was forty feet deep and 400 feet wide.
A series of jetties, canals, rivers, and turning basins now compose the waterway. At the mouth of the channel is the port of Sabine Pass, with jetties extending three miles into the Gulf of Mexico. Twenty-four miles north, up the waterway via the Sabine River, Sabine Lake, Port Arthur Canal, and Gulf Intracoastal Waterway, is Port Arthur. The Sabine-Neches Waterway then splits. To the west the port of Beaumont is nineteen miles up the Neches River from Port Arthur. To the east the port of Orange is fifteen miles above the junction via the Sabine River and Intracoastal Canal. The Sabine-Neches Waterway and Sabine Pass Ship Channel have been tremendously important to Southeast Texas development, despite recurring problems of silting. The system supported more than 45,000,000 tons of cargo annually by the late 1930s. Over 40,000 vessels used the waterway in 1943. In 1979 well over 75,000,000 tons passed through the Sabine Pass jetties, making the Sabine-Neches shipping district the second largest in the state, behind that of Galveston-Houston-Texas City. Petroleum and petroleum-related products shipped in and out of the waterway's four ports, as well as assorted cargoes associated with the Intracoastal Canal, dominate the busy channels.