[4] Headquartered in the Energy Corridor area of Houston, it is majority-owned by PDVSA, a state-owned company of the Venezuelan government (although due to U.S. sanctions in 2019, they no longer economically benefit from Citgo).

Cities Service became the first company in the mid-continent to use the slack demand period of summer to refill depleted fields near its market areas.

In 1931, Cities Service completed the nation's first long-distance high-pressure natural gas transportation system, a 24-inch pipeline 1,000 miles long from Amarillo, Texas to Chicago.

At the same time, the government was nearing completion of a major refinery at Rose Bluff just outside Lake Charles, Louisiana, which would become the foundation of the company's manufacturing operation.

A month before Allied troops landed in France, it was turning out enough 100-octane aviation gasoline to fuel 1,000 daily bomber sorties from England to Germany.

CITGO continued to be only a trademark, and not a company name, until the 1983 sale of what had been the RMT Division of Cities Service to Southland Corporation (now 7-Eleven Inc.).

Cities Service also threatened to dissolve itself by incremental sales rather than being taken over by Mesa, stating that it believed that the pieces would sell for more than Pickens was offering for the whole.

Cities Service Company located what they thought would be a "white knight" to give them a better deal and entered into a merger agreement with Gulf Oil Corporation.

Late in the summer of 1982, Gulf Oil terminated the merger agreement claiming that Cities Service's reserve estimates were over-stated.

Fifty percent of Citgo was sold to Petróleos de Venezuela, S.A. (PDVSA) in 1986, which acquired the remainder in 1990, resulting in the current ownership structure.

[13][14][15][16] In September 2010, in connection with the centennial of its original owner, Cities Service Company, Citgo unveiled a new retail design.

[19] In October 2010, then President of Venezuela, Hugo Chávez, announced the intention to have PDVSA sell its Citgo subsidiary calling it a "bad business" and citing low profits since 2006.

[27] In November 2017, six executives working for Citgo, including five American citizens, were arrested while attending a meeting at the headquarters of PDVSA in Caracas, and as of June 2020 remained imprisoned without consular access and without a trial.

[28][29][30] Although granted house arrest in Venezuela in December 2019, the six men were transferred to harsher conditions in El Helicoide prison following U.S. President Donald Trump's hosting of opposition leader Juan Guaido at the 2020 State of the Union Address.

[35] Other Venezuelan oil executives were arrested in what Bloomberg News described as a "purge" designed to bolster more economic power behind the President of Venezuela, Nicolás Maduro.

[38] Following the death of Hugo Chávez in 2013, his successor Nicolás Maduro presided in office through an era of economic depression caused by decreasing oil prices and sanctions.

[39][40][41] The destabilized economy resulted in hyperinflation, an economic depression, shortages in Venezuela and drastic increases in poverty, disease, child mortality, malnutrition, and crime.

[27] In July 2018, Citgo president Asdrúbal Chávez had his work and tourist visas revoked by the United States and was ordered to leave the country within thirty days.

In March, at the behest of the U.S. Treasury, 35 financial institutions secured a $1.2 billion loan to fund Citgo's daily operations and refinancing, allaying concerns about Citgo's ability to continue operating in the U.S.[5][50][51][52] On June 6, 2019, the U.S. Treasury expanded the sanctions, clarifying that exports of diluents to Venezuela could be subject to sanctions.

[54] In May 2024, Bloomberg reported that opposition-appointed executives of Petroleos de Venezuela were considering placing Citgo into Chapter 11 bankruptcy protection to slow down or completely block the sale of oil assets under the company's control.

7-Eleven spokeswoman Margaret Chabris said "Regardless of politics, we sympathize with many Americans' concern over derogatory comments about our country and its leadership recently made by Venezuela's president.

"[57] 7-Eleven stations subsequently went either unbranded or switched to competitor brands, most notably Marathon, which owned rival chain Speedway at the time.

[62][63] In 2009, a fire at the alkylation unit of the same plant resulted in the release of toxic hydrofluoric acid and the injury of two workers, one with severe burns.

A tank exploded in July 1914,[71] and two major fires occurred at the plant, one in June, 1921 (still under Warner-Quinlan), and another in October, 1938 (under Cities Services).

21 Wood Brothers racing team in NASCAR for many years, with drivers such as Michael Waltrip, Elliott Sadler, Kyle Petty, Neil Bonnett, Morgan Shepherd and Dale Jarrett.

Duno has three overall wins in the Rolex Series and finished second at the 2007 24 Hours of Daytona, becoming the highest-finishing female in the history of the famous race.

[80] Consistent with its former sponsorship of the Boston Marathon, Citgo has for the past few years sponsored an elite level multisport team that competes in both adventure racing and triathlon events throughout the United States.

In 2021, the United Nations called on the US and other countries "to respect, protect and fulfil the human rights of every person affected by direct international action".