(Andy Holzman/Los Angeles Daily News/AP Photo)

Like many young immigrants, Joaquin Arciago Guzman came to the United States looking for the American dream. In 1928, at age 18, he left the Philippines for the Salinas Valley in California to harvest lettuce and cabbage for 40 cents an hour.

Eighty-four years later, at the age of 102, Guzman placed his hand over his heart and took the U.S. Oath of Allegiance Wednesday.

Guzman, along with 7,300 others, participated in a naturalization ceremony at the Los Angeles Convention Center, the Los Angeles Daily News reports.

"I'm happy," Guzman told the Daily News after the ceremony, speaking in Tagalog, the official language of the Philippines.

Only 27 people older than age 100 have become U.S. citizens in the past 50 years, according to U.S. Citizenship and Immigration office. The oldest person to ever receive citizenship was 117 years old.

Guzman's wife, and two of their adult children became U.S. citizens, but Guzman never applied.

Guzman, who has 20 grandchildren, wanted to renew his green card when his niece and caretaker, Julie Guzman, recommended he go for citizenship. But he was nervous about answering U.S. history questions during the interview, she said.

A paralegal helped convince Guzman that citizenship would be wiser, and cheaper, than renewing his green card.

"From there he could not sleep," Julie Guzman said. "He'd always been wondering how he is going to answer the officer. Every day he'd sleep from only 12 to 1 a.m., and he kept reading the history book. Then I said, 'Darling you don't need to memorize that.'"

Even after a doctor signed a waiver saying Guzman is unable to memorize information, he kept studying, his niece said.

Julie Guzman, already a citizen herself, attended the ceremony Wednesday to support her uncle. She said Guzman, who speaks little English, is hard of hearing and most likely couldn't understand the judge administering the oath.

The day of the ceremony, Guzman woke up at 5 a.m., excited and worrying about how his hair looked. During the ceremony, Julie Guzman helped her uncle out of his wheelchair so that he could stand during the singing of the Star-Spangled Banner and the citing of the Pledge of Allegiance. While he stood, Guzman, from North Hollywood, Calif., placed his hand over his heart, next to an American flag in his coat pocket.

"He was so happy. He was so excited," his niece said. "We're so very, very proud of him."