It was Denton who provided the first direct evidence of torture by his captors when, apparently unbeknownst to them, he blinked his message in Morse code in a 1966 interview done with him in captivity.
In the tape, made by a Japanese interviewer and intended by the North Vietnamese as propaganda, Denton also confounded the captors by saying that he continued to fully support the U.S. government, "and I will support it as long as I live." He was tortured again.
"In the early morning hours, I prayed that I could keep my sanity until they released me. I couldn't even give in to their demands, because there were none. It was pure revenge," Denton wrote.
He said his captors never brought him out for another interview. But with the war's end drawing closer, he was released in February 1973.
He was the senior officer among former POWs who stepped off a plane into freedom at Clark Air Base in the Philippines. Denton epitomized the military spirit as he spoke for the returning soldiers: "We are honored to have had the opportunity to serve our country under difficult circumstances. We are profoundly grateful to our commander-in-chief and to our nation for this day. God bless America."
His words and bearing, beamed back to his country by television, gave heart to the military at a time of increasing uncertainty and bitter division over the course of the war.
The tape he had made in 1966 was widely seen, and U.S. intelligence experts had picked up the Morse Code message. But Denton theorized later that his captors likely figured it out only after he was awarded the Navy Cross — the second-highest decoration for valor — for the blinks in 1974.
He was promoted to rear admiral and retired from the Navy in November 1977. Denton then turned to politics, despite having no experience running for a statewide political office. With Ronald Reagan atop the GOP ticket, Denton became the first Republican elected to the Senate from Alabama since the Reconstruction era following the Civil War.