The U.S. set the stage for a coup in Chile. It had unintended consequences at home

Fifty years ago in Chile, the United States worked to end the presidency of an elected Marxist and, in turn, helped usher in an authoritarian right-wing dictatorship.

During the ensuing 17-year rule of Gen. Augusto Pinochet, more than 3,000 people would be disappeared or killed and some 38,000 would become political prisoners — most of them victims of torture.

The brutality in Chile, thousands of miles away, would have repercussions back in the U.S.

When the U.S. role in Chile's democratic collapse became known, activists took action. So did lawmakers. In effect, the coup in Chile led to human rights concerns and Congress taking on a larger role in U.S. foreign policy.

In America, the coup of Sept. 11, 1973, "galvanized public opinion in a way that no other activity, no other coup, no other military dictatorship in Latin America did," says Joe Eldridge, a longtime human rights advocate who was in Chile when it happened. "It was the suddenness, the abruptness in a country that had a long tradition of honoring democratic governance. Chile galvanized, it crystallized in the minds of so many, what was wrong with U.S. foreign policy."

But first, it's necessary to explain what happened. What follows is a history of what led the U.S. to have a hand in the coup, how it occurred, and what happened afterward.

The campaign against Salvador Allende

The U.S. had been meddling in Chile's politics for years by the time 1973 rolled around. U.S. interventions in Latin America go back more than a century.

During the mid-20th century, the Cold War shaped much of policymakers' thinking. Fidel Castro's 1959 revolution in Cuba alarmed Washington about communism and threats of Soviet influence in the