To the strains of “America the Beautiful,” the family of a 22-year-old soldier killed a month ago in Iraq — including the 2-month-old daughter he never met — received papers today that posthumously granted American citizenship to their fallen hero.

Corporal Juan Alcantara, a native of the Dominican Republic who had dreamed of joining the NYPD, was killed August 6 by an explosive in Baqubah. He was assigned to Fort Lewis.

Rep. Charles Rangel presented a certificate of naturalization to Alcantara’s family during a special ceremony at City College today. Alcantara’s family took the oath with about 240 other new citizens.

Alcantara’s fiancee, Sayonara Lopez, 22, fussed with her baby, Jaylani Marie, feeding her a bottle, combing her hair, and rocking her stroller.

“I am happy he received his citizenship,” she said later, “because that is what he wanted.”

Alcantara’s tour in Iraq, which began in June 2006, was extended four months on June 28, a day before his daughter was born.

“It was wrong that he was not allowed to see his daughter,” Alcantara’s mother, Maria Alcantara, said.

Ms. Alcantara wept softly for much of the ceremony, clutching a tiny American flag. She said she couldn’t bear to look at the huge image of her son, superimposed on an American flag, hanging above the podium.

Alcantara is the 103rd soldier to be posthumously granted citizenship in the Iraq war, according to the Homeland Security Department’s U.S. Citizenship and Immigration Services. Five other soldiers from past wars were granted citizenship after they died.

Mr. Rangel thanked Alcantara’s family for standing to take the oath of citizenship, saying he knew how bittersweet the moment must be.

“There is a lot of pain in receiving it,” the Democratic congressman said of citizenship, “if you can’t live to enjoy it.”

He spoke of Alcantara’s dreams when he returned from Iraq — to be a good husband and father, and to follow his sister into the New York Police Department. He urged the family to “pick up the pieces of those dreams.”