From the Alumni Quarterly of University of Illinois:
Robert Grant Holabird, a 1900 graduate, died at Chicago. Upon graduation he became the architectural superintendent for Holabird and Roche (his grandfather's company) and continued in the service of that company until his death. He married Leonora Van Eps on December 16, 1902 and had two children." The children were Margaret and William (1904-1992). Born in Evanston, IL and educated at Yale (1927), William was also a partner in Holabird and Root.