The AR-15 is the most talked about gun in America. But the AR-15's creator died before the weapon became a popular hit and his family has never spoken out.

Until now.

"Our father, Eugene Stoner, designed the AR-15 and subsequent M-16 as a military weapon to give our soldiers an advantage over the AK-47," the Stoner family told NBC News late Wednesday. "He died long before any mass shootings occurred. But, we do think he would have been horrified and sickened as anyone, if not more by these events."

The inventor's surviving children and adult grandchildren spoke exclusively to MSNBC by phone and email, commenting for the first time on their family's uneasy legacy. They requested individual anonymity in order to speak freely about such a sensitive topic. They also stopped short of policy prescriptions or legal opinions. More from NBC News:

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#MakeItStop: Boston Globe Takes Aim at Guns But their comments add unprecedented context to their father's creation, shedding new light on his intentions and adding firepower to the effort to ban weapons like the AR-15. The comments could also bolster a groundbreaking new lawsuit, which argues that the weapon is a tool of war — never intended for civilians. Eugene Stoner would have agreed, his family said. The ex-Marine and "avid sportsman, hunter and skeet shooter" never used his invention for sport. He also never kept it around the house for personal defense. In fact, he never even owned one.

And though he made millions from the design, his family said it was all from military sales. "After many conversations with him, we feel his intent was that he designed it as a military rifle," his family said, explaining that Stoner was focused on making the most efficient and superior rifle possible for the military."

He designed the original AR-15 in the late 1950s, working on it in his own garage and later as the chief designer for ArmaLite, a then small company in southern California. He made it light and powerful and he fashioned a new bullet for it — a .223 caliber round capable of piercing a metal helmet at 500 yards.

The Army loved it and famously renamed it the M16.

But after Stoner's death in 1997, at the age of 74, a semi-automatic version of the AR-15 became a civilian bestseller, too, spawning dozens of copy-cat weapons. The National Rifle Association has taken to calling it "America's rifle." The bullets that tore through the Pulse nightclub in Orlando were Stoner's .223 rounds, fired from a AR-15 spin off made by Sig Sauer.