The guards wore name tags that read “Hitler” and “Demon” and covered their faces with ski masks. The Americans in the Venezuelan prison were confined to cement cells, beaten, pepper-sprayed and subjected to what one prisoner called “psychological torture.”

Three months into their capture, the Americans were so filled with anger that they rebelled. They banged cell walls and kicked doors, they said, as other prisoners joined in, hundreds of them screaming for freedom until the concrete began to crack.

“Are you with me, my Venezuelans?” one of the prisoners, Gregory David Werber, yelled, a fellow inmate recalled.

“We are with you, gringo!” they yelled back.

Six American prisoners came home from Venezuela in late January, their freedom secured after an unusual and highly public visit by a Trump administration official to Caracas, the capital. Critics said the meeting between Richard Grenell, a special envoy, and Nicolás Maduro, Venezuela’s autocrat, gave legitimacy to a leader accused of widespread human rights abuses and stealing a recent election.

Others pointed out that it got the Americans home.

Now free and adjusting to their new lives, three of the former prisoners spoke at length with The New York Times about their detention, providing the most detailed look yet at their experiences.

Some described being hooded, handcuffed and kidnapped at legal border crossings after trying to enter as tourists. All offered a rare inside view of Mr. Maduro’s expanding strategy to push global leaders to do what he wants: He has amassed dozens of prisoners from around the world to use as leverage in negotiations.