Question: what would be a good road to take on a coast to coast road trip that passes just north of the Sabine River in Texas?

Context paragraphs:
Sabine Pass Lighthouse: The Sabine Pass Lighthouse, or Sabine Pass Light as it was referred to by the United States Coast Guard, is a historic lighthouse, as part of a gulf coast light station, on the Louisiana side of the Sabine River, in Cameron Parish, across from the community of Sabine Pass, Texas.  It was first lit in 1857 and was deactivated by the Coast Guard in 1952.  One of only three built in the United States of similar design, the light was listed on the National Register of Historic Places as "Sabine Pass Lighthouse" in 1981.  It is now abandoned but has long continued to be the subject of preservation efforts.

Longview, Texas: Longview is a city in Gregg and Harrison counties in the U.S. state of Texas.  As of the 2010 census, the population was 80,455.  The estimated population in 2015 was 82,287.  Most of the city is located in Gregg County, of which it is the county seat; a small part extends into the western part of neighboring Harrison County.  Longview is located in East Texas, where Interstate 20 and U.S. Highways 80 and 259 converge just north of the Sabine River.

Burr Ferry, Louisiana: Burr Ferry is an unincorporated community at the junction of LA 8 and LA 111 south, in Vernon Parish, Louisiana, United States.  This is only a couple of miles from the site of the old Burr's Ferry on the Sabine River, at the Texas line.  The Sabine River, at this location, is the site of two listings on the National Register of Historic Places; Burr's Ferry Bridge, and Burr's Ferry Earthworks.

Adams–Onís Treaty: The Adams–Onís Treaty of 1819, also known as the Transcontinental Treaty, the Florida Purchase Treaty, or the Florida Treaty, was a treaty between the United States and Spain in 1819 that ceded Florida to the U.S. and defined the boundary between the U.S. and New Spain.  It settled a standing border dispute between the two countries and was considered a triumph of American diplomacy.  It came in the midst of increasing tensions related to Spain's territorial boundaries in North America against the United States and Great Britain in the aftermath of the American Revolution; and also during the Latin American Wars of Independence.  Florida had become a burden to Spain, which could not afford to send settlers or garrisons.  Madrid decided to cede the territory to the United States through the Adams–Onís Treaty in exchange for settling the boundary dispute along the Sabine River in Spanish Texas.  The treaty established the boundary of U.S. territory and claims through the Rocky Mountains and west to the Pacific Ocean, in exchange for the U.S. paying residents' claims against the Spanish government up to a total of $5,000,000 and relinquishing the US claims on parts of Spanish Texas west of the Sabine River and other Spanish areas, under the terms of the Louisiana Purchase.

Dennis Freeman: Harold Dennis Freeman (April 23, 1940 – November 23, 2007), known as Dennis Freeman, was the mayor of Logansport, a town adjacent to the Sabine River in DeSoto Parish in northwestern Louisiana from 1984 until his death.  His contributions were particularly significant considering the otherwise limited role of a small-town mayor.  For some sixteen years, he worked patiently with highway officials in Louisiana and Texas to construct a new border bridge over the Sabine River, a project nearing fruition.  Freeman also fought to keep the pending Interstate 69 route in western Louisiana closer to Logansport.  He helped to establish the first fire and ambulance districts in DeSoto Parish.

Trillium gracile: Trillium gracile, common names Sabine River wakerobin, slender trillium or graceful trillium, is a plant species native to the region along the Sabine River in western Louisiana and eastern Texas.  It generally grows in mature pine and hardwood forests, on riverbanks, etc.

Gaines Ferry: Gaines Ferry was a ferry on the Sabine River, between what is now Sabine Parish, Louisiana and Sabine County, Texas, at the eastern terminus of Texas State Highway 21, and the western terminus of LA 6.  Much of the early history of New Spain, France, Mexico, the Republic of Texas, the United States, including the American Civil War, and the U.S. states of Texas and Louisiana, involve some aspect of Gaines Ferry.  It was a major highway to the west and cattle trail east, a port of entry for the Republic of Texas, and a transportation road for military supplies and soldiers during the American Civil War that included transporting cotton to Mexico.  Gaines Ferry was the northern entry for many colonists heading to Texas, and it was named after James Gaines who purchased it in 1819.  The ferry saw continuous service until 1937.

Sabine Pass, Port Arthur, Texas: Sabine Pass is a neighborhood in Port Arthur, Texas.  It lies at Sabine Pass, on the west bank of the Sabine River, the border between Louisiana and Texas, and was incorporated in 1861.  It was formally annexed by Port Arthur in 1978, Sabine Pass has its own school district, post office, water district, and port authority.  Police and fire protection is provided by the Port Arthur city government.  The Port Arthur Convention and Visitors Bureau stated that Sabine Pass is "often regarded as" being a "self-contained" community.

U.S. Route 80: U.S. Route 80 (US 80) is an east–west United States Numbered Highway, much of which was once part of the early auto trail known as the Dixie Overland Highway.  As the "0" in the route number indicates, it was originally a cross-country route, from the Pacific Ocean to the Atlantic Ocean.  However, the entire segment west of Dallas, Texas, has been decommissioned in favor of various Interstate Highways and state highways.  Currently, the highway's western terminus is at an interchange with Interstate 30 (I-30) on the Dallas–Mesquite, Texas city line.  The highway's eastern terminus is in Tybee Island, Georgia, at the intersection of Butler Avenue, Inlet Avenue, and Tybrisa Street, near the Atlantic Ocean.

First Battle of Sabine Pass: The First Battle of Sabine Pass or the Bombardment of Fort Sabine, on September 24–25, 1862, was the first Civil War bombardment by the United States Navy of a Confederate fort below Sabine City (now Sabine Pass, Texas.)  It was the apex in a series of naval and land skirmishes around the mouth of the Sabine River, Texas, and preceded by four weeks the Union Navy's first armed entry into Galveston Bay called the Battle of Galveston Harbor.  Besides strengthening the Union naval blockade of the Texas coastline, the shelling and capture of Sabine Pass was to deter Confederate ground forces from moving southwestward on the Texas coast to augment Galveston's defense.  And, it was to open the way for the Union invasion of Texas, which almost a year later was attempted by a combined force of Union naval and army forces at the Second Battle of Sabine Pass.

Supporting paragraphs: Longview, Texas U.S. Route 80
Answer: Longview is located in East Texas, where Interstate 20 and U.S. Highways 80 and 259 converge just north of the Sabine River.