Quezada became a national hero by helping to bring to an end the civil war that devastated his country for 36 years. He led two organizations that played important roles in forming a peace agreement: the National Reconciliation Commission, which he headed from 1987 to 1993, and the Assembly of the Civil Society, which he headed from 1994 to 1996. He was also the official conciliator between the government and the guerrillas of the National Revolutionary Unit (1990–1994). His assistant in the peace process, Bishop Juan Gerardi, was murdered in April 1998.