The Reagan Administration did a number of things to try to contain communism in Latin America. For example, they used diplomatic and economic pressure to try to keep Cuba contained and weakened. They used military force in Grenada. However, the episode that is most closely connected with containment in Latin America in the '80s was the Iran-Contra scandal.
In this episode, the Reagan Administration was trying to build up anti-communist forces (called the "Contras") to oppose the leftist government in Nicaragua. One problem with this attempt was that it was illegal under the Boland Amendment that prohibited the use of US funds to overthrow the Nicaraguan government. The Reagan Administration then ended up using funds that it got in various ways (including the secret sale of arms to Iran) to aid the Contras. This was the most high-profile example of US efforts to contain communism in Latin America in the 80s.