CHAPTER 2: SON OF ST LOUIS

Walter Evans’ journey to revolutionizing control systems engineering did not begin in a laboratory or a boardroom—it started in St. Louis, Missouri, a city that had quietly shaped generations of thinkers, innovators, and engineers. His roots, both familial and intellectual, were deeply embedded in this city’s educational institutions, its intellectual circles, and its values. To understand the genesis of Root Locus, one must first understand the environment that nurtured its creator.

LDS Forebearers

All eight of Evans’s great-grandparents were baptized in the UK into the Church of Jesus Christ of Latter-day Saints. All eight sailed from Liverpool, England between 1842 and 1856 on sailing ships chartered by the church. His great-grandparents, grandparents, and parents met at church functions. Evans’s ancestors left the LDS church to join what they called the “Reorganization,” later to be known as the RLDS church. His parents participated socially but did not accept LDS theology. Three of their four children, including Walter, married outside the church and joined mainline Protestant denominations.­­­­­­

Walter Evans was the youngest of four children in a family that placed a high premium on education. His maternal great-grandfather, James X Allen, had served as a surgeon in the Civil War. In the 1870’s he attended a medical college that later formed the foundation for Washington University’s Medical School, a remarkable achievement for the time, setting a precedent for future generations. His maternal grandfather, Samuel Burgess, was a founder of the West End Chess Club, and his wife, Eveline Allen, Burgess, was the United States Women’s Chess Champion in 1906.. His mother, Sybilia Burgess Evans, was second in her class academically. Both Walter’s father, Gomer Evans, and brother, Cedric Evans, graduated from Washington University with Engineering Management degrees, solidifying a family legacy steeped in analytical rigor and disciplined thought.

St. Louis’ academic journey formally began at Soldan High School. It was here that he first encountered both intellectual stimulation and companionship. Geometry was his favorite subject, as evidenced in these comments he wrote to the author’s high school geometry teacher: “Math has always been a game for me and now is a good part of my livelihood. Geometry used to provide (me) a steady diet of looking for a pattern that would lead to a solution before settling down to the detail of writing down all the steps." Moreover, it was in Soldan High’s geometry class that he me Arline Pillisch. Their meeting would mark the beginning of a lifelong partnership. 

Arline was a brilliant student, becoming the valedictorian of their class in 1937. At just 17 years old, the two young scholars set out on their respective paths, but their connection would endure. Her steadfast encouragement, patience, and belief in Evans’ work were essential in his development. While Walter would go on to make significant contributions to engineering, Arline’s role in his life was no less impactful—she was, in many ways, another root of Root Locus.

The Evans Family Farm

Evans’ paternal great-grandfather, Daniel Evans[1], a Welsh collier (i.e., coal miner) was one of four sons born on a farm near the South Wales village, LLandyfeilog, located a few miles from the port city Llanelly. He left the farm to work in one of the massive coal fields in and around Merthyr Tydfil, where he married Gwenllian Williams in 1853.  After they arrived in St Louis in 1856, he went to work in one of the city’s numerous clay mines where he worked 16 years. 

In 1872 he bought 65 acres of property about 70 miles southwest of St Louis, near Sullivan, and became a farmer. His only son, Gomer Daniel Evans, was father to five children, including Evans’ father, Gomer Louis Evans. Gomer Daniel Evans became a railroad engineer.  He was at the helm of a freight train in 1897 when the roadbed, weakened by a storm waters, gave way along a stretch of the Missouri River a mile east of New Haven. All three crew members perished in the river. Gomer’s older brothers went to work, abandoning their education, to make up  for the loss of income, but Gomer, at 12 years of age being youngest, remained in school. He would earn a Wash U engineering administration degree and become a vice president of Wagner Electric, a large St Louis firm manufacturing firm.

In 1917, Daniel Evans, the patriarch of the Evans family, died of pneumonia at age 84. The family cousins hired Earl Burnett to live on the farm as its tenant farmer and they built a cabin on the farm to have a place of their own to stay in when family members, including Walter and his family, went to the farm. They worked summers in the field, shot rabbits with rifles, swam at the “swimming hole” on a tributary of the Merrimac River, and rode the farm’s horses, Toni and Queenie. 

Tragically, Walter Evans’ father, Gomer, the Wagner Electric died due to surgical accident when he was 14, just as his father had lost his father when he was 12 in a railroad accident. A life insurance policy would provide his mother lifetime income. Her sons would earn engineering degrees from Washington University.

The next and perhaps most significant chapter of Evans’ academic development took place at Washington University in St. Louis. This institution, rich with intellectual rigor and pioneering educators, was the proving ground where Evans honed his analytical abilities, built critical relationships, and encountered mentors who would shape his thinking for decades.

Among those mentors were three key professors: Alexander Langsdorf, Frank Bubb, and Roy Glasgow. These men were not just instructors; they were intellectual guides who introduced Evans to the nuances of engineering analysis, mathematical rigor, and practical problem-solving. They instilled in him a disciplined approach to thinking—one that would later manifest in his groundbreaking work in control systems. Fortunately, copies of letters he wrote to his professors, decades after graduation, elucidate the impact these men had on him in his own words. 

To Roy Glasgow, on the occasion of his retirement in 1966, he wrote,

“Dear Dean Glasgow. Fond memories provided by you are so numerous that I will have to limit this letter to those comments which triggered some key decisions in my life, or remarks that I have modified for various occasions. It is hard to believe now that, as a sophomore, I was planning on Engineering Administration. You advised that it would be better to prove myself as an engineer first and worry about the vice-presidency later. The choice at graduation was between GE and Wagner Electric. You advised me of the glowing comments from alums of GE's Advanced Course but warned about the tough entrance exam. Fortunately, the exam was loaded with your kind of problem (which had) set the hook on my liking to attack any problem to achieve as much of a solution as permitted by the initial conditions of knowledge and the time allowed to respond. The (1947 summer) job you set up at Emerson Electric set the stage for root locus by requiring a real working-over of the complex plane in trying to get the frequency response cult off their j axis.”

In a 1961 Evans letter to Dean Langsdorf, he shared what he learned through observation of other students. Evans had a keen interest in understanding how other people ticked throughout his life. Here are his observations.

“At Washington University I found that most students could memorize, something like the vector diagram of a synchronous machine …if the subject was repeated about three times. A basically simpler situation which was not specifically discussed, however, would lose most of them. 

A mid-semester quiz, in DC machinery … involved all dimensions of a motor being doubled. Several students said the test was "unfair" because we had not studied that. I personally learn most effectively by starting with simple examples and working up. Washington University was excellent in that professors such as yourself, Professor Glasgow, Dr. Bubb, or Dr. Middlemiss could and did take a student all the way back to the beginning if necessary and work up to the question at hand….I find that working with my children is a good testing ground for teaching methods because the subject matter is simple, the opportunities frequent, and the reaction clear.”

Frank Bubb was known for his innovative thinking and ability to challenge conventional methodologies. He encouraged students to look beyond textbook solutions and explore new ways of approaching engineering problems.

The relationships Evans forged with his professor went beyond the classroom. Their influence provided him with a foundation that he would later use to reshape the field of control engineering. Although not a straight-A student as Arline may have been, he earned more A’s in the majority of his classes, even English and History. Somewhat surprisingly, his lowest grades, gentlemen “C’s” were in two mechanical engineering classes.

At Washington University, Evans also met John R. Moore, a fellow student and intellectual peer who would become one of the most influential figures in his early career. Moore would later become a key collaborator and professional ally.

The 1930s and 1940s were a period of profound growth in the fields of engineering and mathematics. Universities like Washington University played a pivotal role in fostering the next generation of innovators. Evans’ time at Wash U coincided with a surge in research on servomechanisms, feedback control, and stability theory—topics that would later define his contributions.

While Root Locus was still years away from being formalized, the foundational elements were all present in Evans’ early life:

• Intellectual discipline, inherited from a family that      prized education.
• A network of influential mentors, who nurtured his engineering      abilities.
• A partnership with Arline, whose support provided      stability
• The analytical rigor of      Washington University, which taught him to think.
• John R. Moore, which would later influence his      professional trajectory.

Each of these elements was a root in its own right. Together, they nourished the intellectual ground from which Root Locus would eventually emerge.

By the time Walter Evans graduated from Washington University, he was not just an engineer—he was a thinker shaped by a rich lineage of scholars, strategists, and innovators. His early experiences in St. Louis provided him with the skills, relationships, and intellectual curiosity necessary to make groundbreaking contributions to control systems engineering.

Just as Root Locus would later provide engineers with a visual and intuitive way to understand system behavior, Evans’ own path was shaped by clear and distinct influences. His family, his mentors, his education, and his lifelong partnership with Arline were all essential elements of the equation. These were the roots of Root Locus—deep, interconnected, and essential to the innovation that would follow.

As Evans embarked on the next stage of his journey, he carried these influences with him. His story would soon move beyond St. Louis, but its foundation would always remain firmly rooted in the experiences, relationships, and institutions that had shaped his early years.