Elmer Francis Delventhal

It is with sadness that we announce the death of Elmer "Del" Delventhal, who passed away peacefully in his home in Vernon Hills, Illinois on 22 August 2025 at the age of 91. A gathering to honor Del's life will be held at 2 pm Central Time on September 27th at The Everleigh, 555 Lakeview Pkwy, Vernon Hills, IL 60061. It will be live streamed with an opportunity for remarks. For details, please contact one of the family.

Elmer Francis Delventhal was born in 1934 in Boston. He was dubbed "Del" by the neighborhood kids of his youth, who thought "Elmer" was a funny name. He started working at age 7 and had a career trajectory from shoeshine boy to shoe store floor associate to engineer to math teacher. Del's father was a roofer who gradually became too blind to roof, and the family struggled. He lived at over twenty different addresses all over Boston and New York City before he was 12. He married young and moved the family to a farmhouse on a few acres in rural Connecticut. He fixed it up and dubbed this idyllic estate "Delsdale."

Del was motivated by a strong sense of duty and a drive to volunteer. He lied about his age to join the National Guard at 15. That same year, when there were no volunteers to represent Alpha Company at the boxing tournament, he stepped forward, even though he was underage and untrained. Another example of this tendency came years later when Del finished his night school degree at MIT and was promoted from draftsman to engineer at Raytheon. That same year, Sputnik went up, and President Eisenhower made a speech calling for more math and science teachers to help catch the Russians. Del abruptly left his engineer position to take a temporary spot as a high school math teacher.

Del also had grit and knew how to recover from a blow. He was badly beaten in that first boxing match, crying from frustration and embarrassment when they threw in the towel. He trained at a local gym with his uncle and came back to have a respectable record in future tournaments. Much later, he was the founding faculty advisor of the Central Connecticut State boxing club.

Del's move to teaching also did not start smoothly: contrary to his hopes, that first job was not renewed. Determined to see things through, Del went to work full time as a bus driver, and at the ball-bearing factory on the "graveyard shift," and started studying full time at Wesleyan University towards a masters degree. He barely slept for two years. Within ten years, he was a professor of Math Education at Central Connecticut State. He eventually earned a PhD in that field from the University of Connecticut.

Some who knew Del even thought of him as physically indestructible. One incident which gave that impression happened when he was 15. He was crouched on the shoulder of the highway trying to fix his friend's motorcycle when a bus took the curve too wide and launched him 40 feet, cracking his skull open. Confused and bleeding from his mouth and nose, he argued with the police, and it took two of them plus the paramedic to load him in the ambulance. He woke with his friend next to him, panicked. "What am I going to tell your mother?" "Tell her I'll be home tomorrow." He was ten days in the hospital and needed to relearn how to walk; but healed faster than expected and was apparently no worse for the wear.

The home Del established at the farmhouse in Connecticut did not last long. It fell apart while the 3 youngest of his 5 children were still in elementary school, in a process that deeply affected everyone involved. Del spent the rest of his life working to be there for his kids, at their times of need and their successes, even when sometimes they themselves had complicated feelings. When he remarried he continued to drive his new family across the country regularly to visit relatives. He encouraged all his children to treat each other as brothers and sisters.

In his late forties Del met a friend of his youngest sister, and married her a year later in the Golden Gate Park rose garden in San Francisco. He relocated with her to Saint Louis, Missouri, where they raised two children. In these years Del often missed sleep grading math homework, striving to give each student the maximum amount of partial credit. He retired as "Dr. D," a beloved teacher at Rockwood Summit High School who filled his classroom with great stellated dodecahedra made of string and straws.

As empty-nesters, Del and his wife moved again to the college town of Cookeville, Tennessee, to a freshly-built small house with a big garden. This was their base to travel the country and the world, and to hike the local waterfalls, until that became too difficult. In 2023 they moved to the Chicago area to be near their youngest daughter.

Among the personal accomplishments Del took pride in are marching with his National Guard company at Dwight Eisenhower's first inauguration, and eventually being commissioned a first lieutenant; working as a draftsman on the Mark IV computer at Harvard right after graduating from Boston Technical High School; and running about a dozen marathons between the ages of 40 and 50. He got great satisfaction out of tutoring his children and their friends in math, and in seeing his best students go off to college to study things he couldn't tutor. He had a great memory for popular songs, and could conjure a few verses to match almost any word or phrase. He wrote silly rhyming poetry for everybody, hardly ever sending a letter or a card or a party invitation that was not graced with some original creation. He always teared up at the sad parts of movies. Even when retelling stories from his own life, he would often have to pause, dry his eyes, and compose himself.

Del always maintained a sentimental connection to his early days. He loved raisins in everything his whole life, because that was one of the only treats his family could afford when he was small. Over the years he built a series of shoe-shine boxes, improving on the one he made from pieces of an orange crate when he was seven. Each was fully-equipped with polish and rags. If anyone asked he was happy to take a knee and give them a good shine, and remember working for nickels and dimes in front of Radio City Music Hall.

Del was preceded in death by one son, Dwight; by his parents, Fred and Caroline; by one brother, Freddie, in childhood; and three sisters, Pat, Gerri, and Charlotte, in adulthood. He will be sorely missed by Linda, his wife of 42 years; three sons Dan, Thom and Matt; three daughters Amy, Beverly and Becky; two sisters, Winnie and Linda; as well as numerous grandchildren and great-grandchildren.