Also known as the 100 Hours War, it was a conflict between El Salvador and Honduras that took place in July 1969. Named so for the rioting that took place during the second round of the North American Qualifier for the 1970 FIFA World Cup.
It was fought over a Honduran land reform that stripped Salvadoran immigrants and people of Salvadoran descent of their land and properties, as well as a border dispute. 4,000 people died in the four days of fighting with tanks, artillery, and planes, and the war ended due to intervention from the OAS (no, not the OSS). A peace treaty was signed 11 years after the fighting ended and Honduras won a disputed territory in a ICJ (International Court of Justice) ruling in 1992.
The war caused the 22-years suspension of the Central American Common Market organization — an organization funded by the United States for the purposes of streamlining the economy and easing trade between Central American countries to prevent the rise of left-wing factions in Central America after the Cuban Revolution — causing the situation of El Salvador and Honduras to worsen, leading to re-militarization and the return of hardline authoritarianism in both countries. This would eventually lead to the start of the twelve-years long Salvadoran Civil War (1980 - 1992).
The conflict is also noted for being the last war where both sides fought in the skies using piston-engined fighters, namely ex-American World War II and Korean War fighters.
In the case of soccer, El Salvador won a spot for the World Cup, but lost in the Group Stages.
