[5] Mrs. Annie T. Hamilton of Cuero owned a tract of land in the Brush Country where Three Rivers now sits.

In 1913, Mrs. Hamilton paid the San Antonio, Uvalde and Gulf Railroad to build a depot on her land.

The first glass factory in Texas was built at Three Rivers in 1922 as the gas fuel and local sand was plentiful.

[6] In 1948–1949 the city of Three Rivers gained notoriety as the location of what has become known as the "Longoria Affair" when the director of the only funeral home in town refused to allow chapel services in 1948 for the body of a "Mexican-American" Soldier killed during World War II in 1945.

The new owners of the property asked that the marker not be returned after it was repaired, so it was rededicated and installed in the town square at the entrance to city hall.

[10] According to the United States Census Bureau, the city has a total area of 1.5 square miles (3.9 km2), all land.

The climate in this area is characterized by hot, humid summers and generally mild to cool winters.

The predominant economic drivers for Three Rivers, Texas, are oil and gas exploration, refining, ranching, and hunting.

Choke Canyon State Park offers boating, fishing, camping, educational services, and wildlife viewing.

Some of the antique shops in town and in the neighboring county seat of George West may sometimes carry a few pieces the factory produced.

The Valero Three Rivers Refinery located inside the city limits, is another major employer.