Trained by the American Green Berets, Doe was an ethnic Krahn, part of a rural and deprived tribe in inland Liberia. They did not have much in common with the Americo-Liberian elite who ruled the country.
In 1980, he staged a military coup, executing the president William R. Tolbert, Jr and taking over the country.
During his time in rule he banned newspapers and outlawed opposition political parties. He also entered into deals with the United States government, allowing them to use the country to fight against the Soviet Union and made Liberia part of the Nonaligned Movement to curry favor with the United States. Under his rule Liberian ports were also opened to American, Canadian, and European ships, which brought in a lot of foreign investment from foreign shipping firms and earned Liberia status as somewhat of a tax haven.
On October 29, 1985 Doe was announced the winner of the first multiparty election in Liberia.
However in the late 1980s, as fiscal austerity took hold in the United States and the threat of Communism declined with the waning of the Cold War, the US began cutting off critical foreign aid to Doe.
Doe was disliked by many - even members of his own tribe. He survived a coup attempt, and reportedly had the leader divided into pieces and eaten.
Charles Taylor, an old ally of Samuel Doe's, crossed the Liberian border on December 24, 1989 to fight a guerrilla war against Doe. Taylor had broken out of a United States jail after Doe had accused him of embezzlement. By mid-1990 Taylor controlled the majority of Liberia. Doe was captured in Monrovia by Prince Johnson on September 9, 1990 and was killed shortly thereafter.