It closed a three-year wait for the Dominican-born Polanco. He passed the citizenship test in 2005, but needed a security check to clear.
So he waited.
"This is a long wait, but it was destiny," he said. "I wanted to be here."
Finally, Polanco received a positive response. His file was transferred from Florida, where he spends most of the offseason, to Detroit. The next few mundane steps went quickly, and his long journey from the Dominican ended on Comerica's green grass with a raised right hand and a verbal oath.
Having the ceremony at his home ballpark added extra emotions.
His manager, Jim Leyland, watched from the dugout steps. Tigers coaches and a handful of players, including naturalized U.S. citizen Ivan Rodriguez, viewed, too.
"It means a lot, because I've been here for what, four years, and now the Tigers feel like part of my family," Polanco said. "I feel like I've been here forever, and this is the organization that has given me the chance to play every day finally. To become a citizen here, it's a very important thing for me to do this in front of all these fans that I really appreciate."
The moment almost didn't happen. In 1992, Polanco nearly signed with a Japanese team, the Hiroshima Carp, before accepting an athletic scholarship from Miami-Dade Community College. He's lived in the U.S. since.
"I've lived half of my life here," Polanco said. "I went to college here. My kids were born here. My wife is a citizen, so now, I [was] the only one missing. I'll be part of the family now."
He said teammates such as Miguel Cabrera, who recently became a U.S. resident, have considered becoming a citizen.
"If they ask me," Polanco said, "I'll let them know what I'm going through, what I've been through."
Yes, he'll warn them about the long wait.
But he'll also explain the joys, the benefits of calling themselves an American.
"This country is a country of opportunity, and I work here playing baseball," Polanco said. "It's been very good to me and my family. God bless America."