Kevin Spacey. [Photo/IC]

Nixon had not begun his secret Oval Office recordings, so the screenwriters relied largely on firsthand accounts from Presley confidant Jerry Schilling and Nixon aide Bud Krogh.

Shannon, whose Presley is quiet, lonely and reflective, never imagined himself playing the "king of rock 'n' roll".

"I didn't go into it being a huge Elvis fan. I didn't have his records or anything," the Kentucky-born actor says. "But I am really happy I had a reason to investigate Elvis because there is nobody else like him, not just in terms of the scope of his fame but in the unique construct of his life. I think he was always trying to figure out, 'Why me?'"

Shannon listened to interviews and visited the tiny apartment in Memphis where Presley spent his teenage years. He also learned karate for a scene in which Presley demonstrated his black belt moves for an astonished Nixon.

Spacey relished the chance to play a very different kind of president, and to present a rarely seen side of Nixon.

"I just hoped that if I was able to create a Nixon who had enough of the qualities about who he particularly was, that people wouldn't think about Frank Underwood, even though I am on an Oval Office set."