It’s intriguing, and more than a little amusing, to imagine contemporary American music stars serving in the military. How would Kanye West fare in the Air Force? Would Adam Levine cut it in the Army? How long would Eminem last in basic training? (Actually, Marshall Mathers would probably stick it out for a while; he’s got some authority issues, of course, but he’s a tough little bastard.)

But when a young man who was, at the time, the biggest musical star on the planet was drafted into the United States Army back in 1958, the uniform seemed to fit. Sure, Elvis Aaron Presley often affected a sneer that would drive most drill sergeants to near-apoplexy, and his pompadour was hardly the sort of hairstyle one associated with America’s fighting men. But Elvis was a good ol’ boy, born in Mississippi and raised in Tennessee, and maybe his humble Southern roots allowed for a more seamless transition from pop-culture icon to buck private. Maybe he was eager to serve his country. Maybe he was tired of being an enormously popular and rich rock and roller and simply longed for the anonymity of Army life. (Unlikely, we know.)

Whatever the reason, for a couple of years, Elvis Presley looked like he belonged in a uniform — and by all accounts, his brothers in arms saw what he was made of, and accepted him as one of them. It was impossible, of course, for anyone to pretend that Elvis was just another soldier; but he worked hard to fit in and to do what was asked of him, and after two years, when Sgt. Presley was honorably discharged, it was evident that the boy from Tupelo had grown up.

It was also evident, though, that Elvis was hardly heartbroken about leaving the military. His two years serving in Germany had shown the world, and had shown Elvis himself, that he could handle something more than a guitar, and could perform tasks that didn’t involve gyrating in front of screaming bobbysoxers. In 1960, it was time to get back to doing what he did best: it was time to leave Sgt. Presley behind, and be Elvis again.

Here, LIFE.com presents a series of photos — most of which never ran in LIFE magazine — showing Elvis, along with his 15-year-old girlfriend, Priscilla Beaulieu, in Germany on the day he left for the States (March 2, 1960), and Elvis again at Fort Dix, New Jersey, where he landed on March 3, sans Priscilla. He was officially discharged from the Army on March 5. These pictures, by LIFE photographers James Whitmore and Al Fenn, capture a moment in Elvis’s life when he was poised to remind everyone who might have doubted it that, despite two years of taking orders, he was ready to again be the King.

A few weeks later, in its March 14, 1960, issue, LIFE put it this way to its millions of readers: