Frederick William Pfeiffer Jr. , 88 years old and a longtime resident of Apple River, Illinois, passed away peacefully in Dubuque, Iowa on March 4th, 2025.

Born the son of Margaret Alice Thomas and Frederick William Pfeiffer Sr. in Washington, D.C. on April 5th, 1936, Frederick grew up in Hyattsville, Maryland where he graduated from Northwestern High School in 1954 and the University of Maryland in 1958 with a mechanical engineering degree.

After a brief stint working with radar systems for the U.S. Government, Frederick shifted his career to finance where he first worked as a stock broker in New York City, and then as an independent floor trader at the Chicago Mercantile Exchange. He also ventured into several businesses including hog farming and oil exploration.

In retirement, Frederick spent his time building two homes, one in Apple Canyon Lake, Illinois and the other in St. John, U.S.Virgin Islands, playing bridge, playing the piano, gardening, supporting the local wildlife, and closely following global affairs.

Preceded in death by his former wife Solveig Henning Pfeiffer and youngest son Erik Ingolf Pfeiffer, Frederick is survived by his eldest son Frederick William Pfeiffer III, his longtime partner Donna J Wilson, his sister Joan Pfeiffer Riggin, his nieces Cynthia and Christine, his Thomas cousins, and his many cherished friends. Memorial donations may be directed to the American Heart Association and/or the Audubon Society.