It looks to me like it said that in both the original and revised bios. It's a strange thing to say though since the first time he set foot in Chicago was 1984 and he would have been 23 yrs old. "Composite" childhood?
Mr. Obama's Neighborhood
The Democratic candidate has made his home in Chicago's Hyde Park, a place that's not like any other in America."He first moved there in 1984, when he came to Chicago as a community organizer, and he returned after graduating from Harvard Law School."
He lived with the Ayres family when he wasn’t at school. They paid for his education.