Hartman, who was chosen No. 30 by the Blackhawks, has 10 goals and a team-leading 21 points in 20 games with the Plymouth Whalers in the Ontario Hockey League this season.
Last season he had 23 goals and 60 points in 56 games with Plymouth and had three points in seven games to help the United States win the gold medal at the 2013 IIHF World Junior Championship in Ufa, Russia.
This is a great day for me. This is something I've been thinking about for a long time. This is a great opportunity that the St. Louis Blues organization, (owner) Tom Stillman and Doug Armstrong are giving me and trusting me in doing...This is going to be a great challenge for me.
— Martin Brodeur, after announcing his retirement as an NHL player and becoming a senior adviser with the Blues on Thursday