[18] Kilgore was founded in 1872 when the International–Great Northern Railroad completed the initial phase of rail line between Palestine and Longview.

The rail company chose to bypass New Danville, a small community about 10 miles (16 km) southeast of Longview, in lieu of a new townsite platted on 174 acres (0.70 km2) sold to the railroad by Constantine Buckley Kilgore, the town's namesake.

[19] A post office was built in Kilgore in 1873 and with a station and transportation for getting commodity crops to market, the city soon began drawing residents and businesses away from New Danville.

Prosperity came to a halt, however, when Kilgore was dealt severe blows by a steep decline in cotton prices (on which most of the town's economy was still based), and the effects of the Great Depression.

Businesses began to close and, by the middle of 1930, the population had fallen to 500; the community appeared destined to become a ghost town.

Many Blacks joined the Great Migration out of the South to northern, midwestern, and western cities for work.

Kilgore's fortunes changed dramatically on October 3, 1930, when wildcatter Columbus M. "Dad" Joiner struck oil near the neighboring town of Henderson.

The well known as the Daisy Bradford #3, marked the discovery of the vast East Texas Oil Field.

Seemingly overnight Kilgore was transformed from a small farming town on the decline into a bustling boomtown.

The explosive growth left most civic services overwhelmed, and as a result Kilgore was forced to incorporate in 1931.

With the city flooded with male workers and roustabouts, law enforcement struggled to keep order among the shanties, tents, and ramshackle honky-tonks that crowded Kilgore's main streets.

[36] The Kilgore Trails System is 3.5 miles (5.6 km) and was designed for walkers, runners, and cyclists.

At the federal level, the two U.S. senators from Texas are Republicans John Cornyn and Ted Cruz.

Most of the city is within the Kilgore Independent School District, which covers sections of Gregg and Rusk counties.

[42][43] A small portion of the city in Gregg County is within the Sabine Independent School District.

[45] A proposal is in the works for a over 200mph high-speed rail system from Dallas/Fort Worth to Atlanta, Georgia along the I-20 corridor, currently named the I-20X, that will pass directly through Kilgore, bringing passenger rail service to that corridor for the first time since the Texas and Pacific's unnamed successor to the Louisiana Eagle in the late 1960s.

[47][48]This initiative promises to support regional development, reduce car dependency, and create jobs in areas like Tyler, Kilgore, and East Texas.

Opened in phases from 2018 to 2020, the Creekside Trail follows Bighead Creek with multiple access points.