Funeral Details

D. Jeffrey Blumenthal, known as Jeff, passed away suddenly at the age of 84 on March 14, 2025. He was a dedicated family man, an accomplished academic, and a successful professional who had significant influence in the fields of engineering, business and his community.
Jeff was born on June 12, 1940, in Evanston, IL to Jeanne (Newberry) and Harold Blumenthal. He lived in Highland Park, IL until college. Jeff attended Lake Forest Academy where he excelled academically and athletically, serving as captain of the hockey team and participating in track and football. He continued his education at Cornell University, majoring in Engineering Physics, and later attended Stanford University, where he earned a Master of Electrical Engineering and an Engineer's Degree in Engineering Economic Systems.
Jeff's professional journey began as a Senior Research Engineer at Sylvania, GT&E in Mountain View, CA during the Vietnam War, where he held top secret clearance. He later worked at Bolt, Baranek & Newman in Cambridge, MA, contributing to projects that eventually led to the development of the Internet. In 1978, Jeff founded the Jeffrey Corporation, specializing in business turnaround strategies, loan workouts, process engineering, activity-based costing, and startup business development.
In 1985, Jeff joined Follett Corporation, a leader in the educational services industry, where he held several key positions until his retirement in 2007. He authored a widely distributed book on retail product marking standards in college stores. From 2007 to 2013, he worked for Blumenthal-Hart Ltd. in various roles.
An avid learner and hobbyist, Jeff enjoyed ham radio, cycling, and volunteering. He learned morse code and was an Expert Ham Radio (KB9CZ) operator until his death. Jeff loved to ride and fix bicycles. After retirement he was a volunteer at Working Bikes, a 501(c)3 in Chicago. He also belonged to a senior bicycle group.
He held various civic roles and taught as an adjunct professor at several institutions. At age 32, he was the youngest trustee to be elected to the Deerfield Village Board. He also was Chairman of the Deerfield CATV Committee, Board of Directors and Treasurer of the Book Industry Study Group, and Chairman of the Book Industry Systems Advisory Committee.
Jeff was a longstanding member of the Economic Club of Chicago, The Union League Club of Chicago, Treasurer of Union League Engineers’ Foundation, The Columbia Yacht Club of Chicago, The National Association for Business Economics, Co-founder of the NABE/CPS Economics After School Club, Chicago Principal for a Day, Member of the Medill School Turnaround Project, and a MENtor in the Real Men Read Project.
In the late 70’s and early 80’s, Jeff was an Adjunct Professor at the J.L. Kellogg Graduate School of Management in the Managerial Economics & Decision Sciences Department where he authored his own textbook. In the mid 80’s, Jeff was an Adjunct Professor at Lake Forest Graduate School of Management where he taught courses on Strategic Planning & Quantitative Methods. From 2011-2013 he was an Adjunct Professor at Harold Washing College where he taught Statistics.
He rode a Kawasaki Vulcan Drifter for several years and belonged to the Chaiway Riders Motorcycle Club. Jeff loved the Lyric Opera of Chicago, and the Joffrey Ballet. He served on the board at the ParkShore Condominium Association, heading the Building Commission at a time when there was a major capital project that needed someone with his skills to pull it off.
Jeff was a devoted husband of almost 59 years to Joan (née Hartstein), a loving father to Andy Blumenthal of Fayetteville, GA, and to Marianne (Louis) Soto of Libertyville IL. He was known as Papa to his grandchildren; Nate Blumenthal, Mia Soto, and AJ Soto, and had many cherished nieces, nephews, and friends. He is preceded in death by his parents Harold and Jeanne Blumenthal, sister Shelia Spargo, and brother David Blumenthal.
Jeff is remembered for his wit, kindness, and contributions to both his family and community. He will be dearly missed by all who knew him.
Services are private. A Celebration of Life will be held in May.
In lieu of flowers, contributions may be made to Lake Forest Academy, The Lyric Opera of Chicago, or The Joffrey Ballet.
Arrangements by Chicago Jewish Funerals - Skokie Chapel, 847.229.8822, www.cjfinfo.com