"He seemed normal. He ran and jumped and played like other kids. He smiled all the time.
"But he didn't talk. He understood everything we said to him. But he didn't say anything to us."
Eric, 40, who had two other fully functioning sons, sought the advice of pediatricians. They weren't much help.
"They had no clue. They actually turned us away and said don't worry about it. It was easy for me to accept their advice because he seemed so normal."
Until one night when he and Elijah saw some people on TV talking about autism. They described some quirks he had seen in Elijah.
"I thought, 'This is why he's not talking,' " Williams said. "It took me a while to understand the different stages. I had to figure out where he was on that spectrum. I needed to find out where to get him some help."
As it happens, the most important institutional resource available to him was a Philadelphia public school. He enrolled Elijah at Rhoads Elementary School, at 49th and Parrish streets.
Elijah thrived in the autistic-support program at Rhoads. By age 6, he said his first word - "dad." He now has a large vocabulary and seems well-adjusted.
But he's 12 and has "aged out" of the Rhoads program. Next month, he will be enrolled at the Martha Washington School.
"I'm not worried about him there," Williams said. "I hear nothing but great things about the teaching staff and program at that school."
But the problem for low- to moderate-income parents of autistic children is a lack of after-school programs to build on the progress they make in school.
Williams, who is a freelance audiovisual technician, has made that his mission. He has spent the last six years and a large chunk of his personal income attempting to build an after-school program.
"What's needed are programs that operate from 3 p.m. to 6:30 that offer the kind of cognitive-, social-, speech- and behavior-therapy help they get in school.