Any time he got a break from his job cleaning the fourth floor at the Nassau County Supreme Court, Joe Sarpong would duck into a closet and study a notebook.

"How many amendments are there to the Constitution?" he would ask himself, or, "How many voting members are in the House of Representatives?"

Sarpong, 36, who was born in Ghana, had a lifelong dream: to become a United States citizen. But a taxing job and a long commute from the Bronx were the least of his obstacles.

Sarpong is deaf and cannot speak. And when he moved to New York from Ghana in 1999, he could not communicate with anyone here, even in sign language.

"But I loved America," Sarpong said recently through a sign-language translator. "It was beautiful. It was big. I wanted to stay here."

As a child in Ghana, Sarpong, who has been deaf since birth, struggled to find a place in the world. His father, frustrated by his disability, abused him when he was small and then left altogether, Sarpong said. His mother then had to move abroad to make enough money to support him. In 1999, Sarpong decided it was time to move to the Bronx to be with his mother.

At first he was isolated and frightened, unable to communicate or find work. Then he discovered Mill Neck Services for Deaf Adults, a nonprofit program that helps people train for, find and succeed in jobs. Through that program, Sarpong found his job at the Nassau County Courts working for Corporate Source, an organization that places disabled adults.

Soon, as he pushed his mop through courtrooms and judges' chambers, Sarpong began to form wordless friendships, built mostly on smiles. One day as he passed through the chambers of Judge Roy Mahon, he showed the judge's clerk, Diane Baruh, a copy of his practice citizenship test, and wrote down a confession. "He said he had a big desire to become a citizen," Baruh said.

Baruh helped Sarpong collect his papers, and find a sign language interpreter at the immigration department in Manhattan. After a number of setbacks and false starts, Sarpong and Baruh took a day off work in May and headed to Federal Plaza in Manhattan. Sarpong waited nervously until he heard the news of a lifetime -- he had passed his test.

"I was so proud," said Sarpong, who signs with such emphatic movements and dramatic facial expressions that it is sometimes possible to understand what he's saying even without words.

Baruh and others organized a party for their new friend in Mahon's chambers, drawing judges, lawyers and court staff from across the building, as well as Sarpong's friends from Mill Neck Services.

Today, on Sarpong's first Independence Day, he said his only plan is to go to Manhattan and see the fireworks. But he says he is overwhelmed by the significance of his first July 4 as an American.

"I just can't believe God gave this to me," he said. "Sometimes I feel like I am so excited it almost hurts my heart."