[8] The Gulf Coast gained its present configuration during the most recent glacial period approximately 18 ka (thousands of years ago).

Low global sea levels allowed the Texas mainland to extend significantly farther south than it does presently, and the Trinity River had carved a 170-foot (52 m) deep canyon through present-day Bolivar Roads (the exit of the Houston Ship Channel) on its way to the coast.

[9] As the glacial period came to a close, rising sea levels initially filled this narrow canyon, followed by the broad lowlands of present-day Trinity Bay.

When he abandoned the base, it was then taken over by pirate Jean Lafitte, who temporarily transformed Galveston Island and the bay into a haven for outlaws before being ousted by the United States Navy.

[13] After the election of Abraham Lincoln in 1860, residents of Galveston strongly supported secession and sided with the Confederacy as the Civil War broke out.

The city of Galveston became a major U.S. commercial center for shipping cotton, leather products, cattle, and other goods produced in the growing state.

[18] Growth moved inland to Houston, as fear of the risks posed by establishing businesses at Galveston limited the island's ability to compete.

[24] Extraction of oil and groundwater, as well as large wakes from increasing shipping in the bay, led to land subsidence and erosion along the shoreline, especially in the Baytown–Pasadena area.

[25] Over the past few decades, approximately 100 acres (40 ha) of the historic San Jacinto battleground has been submerged; Sylvan Beach, a popular destination in La Porte, has been severely eroded, and the once prominent Brownwood neighborhood of Baytown has been abandoned.

[26][27] Today, the bay is a major destination for recreational and tourist activities, including boating, ecotourism, and waterfowl hunting.

On February 23, 2019, the Boeing 767-375ER(BCF) crashed into Trinity Bay near Anahuac, Texas, killing both crew members and a passenger, at approximately 12:45 CST (18:45 UTC).

[30] Investigators from the Federal Aviation Administration (FAA), Federal Bureau of Investigation (FBI), and National Transportation Safety Board (NTSB) were deployed to the scene while dive teams from the Texas Department of Public Safety, Houston, and Baytown police departments located the aircraft's flight recorders.

[35] An approximate 6.5 mi (10.5 km) span of the Gulf Intracoastal Waterway was shut down around the bridge in order to help crews clean up the oil spill.

[45] A proposal to build a flood barrier system to prevent against future storm surge, the so-called Ike Dike, has been considered by the state government.

[50] The deeper navigation channels of the bay provide suitable habitats for bottlenose dolphins, which feed on the abundant fish varieties.

[51] Additionally, the bayous, rivers, and marshes that ring the bay support their own collection of ecosystems, containing diverse wildlife and enabling freshwater farming of crawfish.

The 2019 report assigned a "C" grade for toxins in bay sediments, citing water and soil pollution, wildlife habitat loss, and the impacts of climate change as challenges facing the estuary.

The presence of the San Jacinto Pits Superfund site in the Houston Ship Channel, which contains large amounts of dioxin, is considered a significant threat to the bay's health.

[55] The entire bay is covered by seafood consumption advisories set by the Texas Department of State Health Services, but the strictness of these standards varies by location.

[57] Excessive ozone levels can occur due to industrial activities; nearby Houston is ranked among the most ozone-polluted cities in the United States.

[59] Galveston Bay is located in Greater Houston, which is the fifth largest metropolitan area in the United States, and home to one of the nation's most significant shipping centers.

It is a partially man-made feature created by dredging the Buffalo Bayou, the ship channel subbays, and Galveston Bay.

[62] A large commercial fishing industry has grown around Galveston Bay, with significant production of shrimp, blue crab, eastern oyster, black drum, flounder, sheepshead, and snapper.

This sort of ecotourism generates millions in annual revenue for Chambers County, which is home to the Anahuac National Wildlife Refuge and High Island.