Technologists used artificial intelligence to recreate the speech that President John F. Kennedy planned to deliver in Dallas on the day he was assassinated. (The Times of London)

When John F. Kennedy’s convertible was crossing Dealey Plaza, he was five minutes from the Trade Mart in Dallas, where 2,000 people were waiting to hear him give a speech. The president never spoke those words.

Until now. Sort of.

Fifty-five years later, in one of the many groundbreaking and controversial ways history is becoming less about dates and more about data, technology has extended Camelot by another 18 minutes. JFK finally delivered that last speech in his own “voice.”

Taking more than 116,000 snippets of speech from samples of the 35th president’s other recordings, a Scottish “voice cloning” firm has produced a Kennedy-esque rendition of his final scripted words:

“America’s leadership must be guided by the lights of learning and reason,” a virtual version of that unmistakable Boston Brahmin accent intones, “or else those who confuse rhetoric with reality and the plausible with the possible will gain the popular ascendancy with their seemingly swift and simple solutions to every world problem.”

The effect is powerful, if not perfect. At its best, Kennedy is clearly doing the talking; hearing him complete his mission for that day has moved many listeners to tears. At its worst, a robotic inflection on some phrases makes it sound like JFK inhabits an automated voice mail system. (“Press two for racial justice in our time.”)