McCreery's win followed an evening of star-studded performances by Beyonce, Lady Gaga, Judas Priest, Tom Jones, Tony Bennett and Bono singing alongside "Idol" contestants.
It was the first-ever, all-country final in "American Idol" history, with Lauren Alaina taking on McCreery for the crown.
USA Today writer Brian Mansfield said country fans have always been a big part of the "Idol" audience. In Season Four, they crowned Carrie Underwood the winner and continue to make her one of country's biggest stars. Underwood recently surpassed Season One winner Kelly Clarkson as "Idol"s biggest earner.
This season, however, country fans were a "force."
"It didn't really surprise me that both Scotty and Lauren made the Top 5, but it did surprise me that they went into the finals together," Mansfield said. "I didn't realize there was that much country to split."
Both contestants had been fan favorites all season, but McCreery's popularity never seemed to wane. "From what I've heard throughout the season, it's been Scotty and everybody else," Mansfield said. "He dominated the vote from very early on."
While McCreery never landed in the bottom three, Alaina had to fight her way back to the top. She had an ally in judge Steven Tyler, who singled her out from her initial audition.
"When I first heard Lauren, seven months ago, it was the second city," Tyler said at a post-finale-show news conference. "You have to go through so many kids and she sang. She doesn't try to hit the notes, the words just go to that place. Everybody else is trying to hit the notes, and she's never had that problem with pitch. Maybe bad songs, but she's been perfect and right and great. I circled her months ago and said, 'American Idol.' Her and about six or seven others, but I heard her first. I mean, how does a 15-year-old sing like that? How does that happen? That's magic, that's the gift, and that's what we're looking for."
Alaina, now 16, struggled all season with nerves and confidence, but she picked the right moment to peak. After Ryan Seacrest's announcement at the top of Tuesday's show that Alaina had blown out a vocal cord, the 16-year-old Southern belle declared, "I'm here, I'm ready to sing and I'm fine -- don't worry about it."
Mansfield said Alaina's performance Tuesday was "probably her best night of the season, while Scotty had probably his worst night."
The judges praised both but seemed to give the edge to Alaina.
"This is a very tight race tonight, but Lauren, with that song, you may have just won," Lopez said, after Alaina performed her Jimmy Iovine-chosen song "Like My Mother Does," bringing her mother to tears.
Ultimately, Lopez declared the race too close to call, but Tyler wasn't shy. "Sorry, Scotty, Lauren gets it hands down," he said.
Still, McCreery was favored to win going into tonight's results show. The Garner, N.C., native with the "aw shucks" attitude seems ready to step right into a music career.
But Mansfield says not so fast. Nashville program directors aren't exactly clamoring for records from McCreery or Alaina, for that matter. He said teenage guys historically don't do well on country radio. But McCreery, who has built a following through "Idol," could change that, becoming the "country equivalent of Justin Bieber."
Alaina, he said, might have an easier time breaking into country radio because there's a track record of other young female success stories, such as Taylor Swift and LeAnn Rimes. Country's most successful women are in their 20s, while country's biggest men are in their 30s.