John "Jack" Lieffort

John "Jack" Lieffort, 98, of Milbank, SD, and formerly of Chicago, IL, passed away on Tuesday, October 14, 2025, at Milbank Area Hospital - Avera Health in Milbank.

Jack requested no formal services. Inurnment will be at Evergreen Cemetery in Chicago, IL, with wife, Adeline, and their two beloved poodles at a later date. 

John L. “Jack” Lieffort, son of Albert and Ellen (Heffernan) Lieffort, was born on December 8, 1926, in Milbank, South Dakota. Jack graduated from Milbank High School in 1945. After graduation, he served in the U.S. Army from 1945 to 1947 at Fort Snelling in Minnesota and at Fort Leavenworth in Kansas. Jack attained the rank of corporal and was honorably discharged.

In 1951, Jack received his bachelor’s degree in business administration from the University of South Dakota. Upon graduation, he was recruited to work for Arthur Andersen & Co. in Chicago, Illinois. While in Chicago, in 1958, Jack became a Certified Public Accountant (CPA). In 1962, Jack became the Vice President, Controller, and CFO at R. Cooper Jr., Inc., a distributor of household appliances. He worked at R. Cooper Jr. until he retired on December 31, 1991.

After he moved to Chicago, he met his first wife, Adeline Rahn. They were married on July 20, 1957. They enjoyed traveling and shared an appreciation of artwork and pottery from the many places they visited. After 45 years of marriage, Adeline died on September 10, 2002. They had no children.

After Adeline died, Jack made frequent trips to Milbank to visit his sister, Agnes Engebretson, and his sister-in-law, Florence Lieffort. During these visits, he met Sylvia (Stengel) Konstant. In 2010, Jack moved to Milbank. Jack was united in marriage to Sylvia on August 14, 2010, at Emanuel Lutheran Church in Milbank and gained four adult stepchildren and their families. The couple enjoyed their time together traveling to Arizona in the winter months, attending art shows, and enjoying the companionship of family and friends. Sylvia passed away on June 12, 2013.

In October of 2017, Jack moved to Sioux Falls and lived at Grand Living at Lake Lorraine (now known as Legends on Lake Lorraine). He had friends and family close by, which he took great delight in. Jack was no fan of the long South Dakota winters, but he found pleasure in attending musical events, movies, and having conversations with new friends as a meaningful way to pass the time. Jack moved to The Wellshire – Park Place Assisted Living in Milbank in the fall of 2025. He died peacefully at the Milbank Area Hospital on Tuesday, October 14, at the age of 98.

Survivors include his step-children: Lyn Konstant of Sun City West, AZ; Laurie Settje of Corona, SD; John (Kathy) Konstant of Milbank, SD; and Kathryn Hoskins of Sioux Falls, SD; eight step-grandchildren: Martha Carlson (Tom) Guyer of Kirkwood, MO; Lucas Carlson of Kirkwood, MO; Christopher Settje of Corona, SD; Craig (Rachel) Settje of Champlin, MN; Catherine Settje (Michael) Hanten of Sioux Falls, SD; Dr. Kylie Poel (Dr. Greg) Thompson of Shoreview, MN; Samuel Hoskins of Sioux Falls, SD; and Elizabeth Hoskins (Hunter) Stanek of Farmington, MN; and six great-step-grandchildren; Millie and Rose Guyer; Carter Settje; Emilia Settje; Tate Hanten, Franklin Thompson; and Otto and Brooks Stanek. In addition, he has numerous nieces and nephews.

He was preceded in death by his parents: Albert and Ellen Lieffort; two wives: Adeline and Sylvia; three brothers: James, Alvin, and Lawrence; three sisters: Agnes Engebretson, Edith Shiffer, and Joyce Lueken; and two step sons-in-law: James Carlson and Ronald Settje.

                                                                                                                                                Written by Jack's family. 

Any memorials in honor of Jack can be sent to:

Beacom School of Business at the University of South Dakota: 414 E. Clark St., Vermillion, SD 57069.