Patricia Brown Holmes could have used a posse. In the fall of 1979, Holmes arrived at the University of Illinois. After finishing No. 1 in her class at Corliss High School in the South Side neighborhood of Pullman, she chose U. of I. for its industrial engineering program. The rigor of higher education was not her challenge. “I was the only black person I saw all day in my classes,” Holmes said. “I couldn’t study with people because there was no one who wanted to study with me. Everything I …