Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
The 1989 CONCACAF Championship was the tenth and final edition of the CONCACAF Championship held under the format of serving as qualification to the 1990 FIFA World Cup and having no host nation for the final round. The tournament would be succeeded by the CONCACAF Gold Cup in 1991.
Costa Rica narrowly emerged as champions on goal difference to win their third title and participate in their first World Cup. The United States finished runners-up by virtue of one goal and qualified for their first World Cup in forty years. The U.S. gained their first World Cup qualification in 40 years by beating Trinidad and Tobago in their last game by 1–0, with a goal dubbed "The Shot Heard around the World".
A total of sixteen CONCACAF teams entered the competition. However, FIFA rejected the entry of Belize due to debts to FIFA.
Five teams qualified from the two stage qualification process that ran from April to November 1988. Mexico were disqualified during this stage after having been found to have fielded over-aged players during the 1988 CONCACAF U-20 Tournament. Their scheduled opponents Costa Rica therefore advanced to the Final Round unopposed.
The El Salvador–Trinidad and Tobago match was played on neutral ground in Honduras instead of in El Salvador.
The El Salvador–United States match was played on neutral ground in Honduras instead of in El Salvador.
^ Both matches between El Salvador and Guatemala were originally scheduled to be played in Guatemala; later it was agreed that they would not be played, due to their lack of importance (neither team could have qualified for the World Cup by winning both matches).