Maggie Daley, the wife of longtime Chicago Mayor Richard M. Daley, died Thursday at the age of 68 after suffering for years from breast cancer. Daley was considered the driving force for Chicago’s arts and education during her husband’s 22 years in office. Born in the Pittsburgh suburbs, Daley moved to Chicago to work at Xerox, and she married the son of one of Chicago’s most powerful families in 1972. Their third child, Kevin, was diagnosed at birth with spina bifida, which he succumbed to three years later. Once her three surviving children were in school, Daley began playing a more active role in the city’s cultural and civil life and serving on the auxiliary board of the Art Institute of Chicago and later going against her husband’s efforts to tear down the former main branch of the Chicago Public Library.