Herbert Ellsworth Slaught was the youngest of his parents' seven children, having four older brothers and two older sisters. The name Ellsworth was chosen by his parents to honour Colonel Ephraim Elmer Ellsworth who had been killed in the civil war on 24 May 1861. Herbert's parents had been married in Hector, New York in 1838 and had lived mainly on their farm on the east shore of Seneca Lake. However, at the time that Herbert was born, his father was working in Watkins, New York and the family had moved there although it was only about 10 km from their farm. He was brought up on the farm on Seneca Lake but an event which greatly affected him for the rest of his life happened when he was three years old :-
Following an escapade in the local swimming hole with his older brothers on a cool day, he had an attack of rheumatic fever. For a period of several weeks he suffered severely. As a result of this sickness his right foot and leg never developed properly. He was crippled the rest of his life. It was necessary for him to walk with a cane until many years later when he, with unusual mechanical skill and ingenuity, perfected a shoe which enabled him to walk in comparative comfort and in fairly normal fashion.
However, despite these problems, he had a good upbringing on the farm :-
In spite of his lameness, suffering, and frailty, there were numerous delightful experiences during his years on the farm. Among those related in his Reminiscences are his are his prankish adventures with his dog, Fido; his experiences in helping the older boys make maple sugar; long sittings in the grape arbor and under the fruit trees of the large orchard; and learning to telegraph on instruments which he and the other boys made with their own hands.
When he was 13 years old, his family lost their farm and were forced to move. This was as a result of failing to pay the mortgage since his father had drifted into "moral delinquency" and left the family. Perhaps, as Gilbert Bliss relates in , this was a blessing in disguise:-
... Slaught himself has said that he would probably have spent his life working on the farm if it had not happened, and the farm was apparently not a very good one.
Slaught, with his invalid mother, a sister and two brothers, moved to Hamilton, New York, in 1875. They travelled there on a horse and cart, salvaged from their farm, towing one cow and carrying a few household goods rescued from the farm. Slaught attended Colgate Academy in Hamilton until he graduated in 1879. A major advantage of the move to Hamilton was that he entered Colgate University after graduating but was still able to live at home. He had to support himself both through college and through his undergraduate studies. After an outstanding undergraduate career he graduated with an A.B. in 1883. His main interest had not been mathematics but rather classics and he had hoped on graduating to find a position in this area. However, he was offered the post of instructor in mathematics at the Peddie Institute in Hightstown, New Jersey and he quickly accepted. Very quickly he impressed everyone with his abilities to teach and his administrative abilities.
Slaught was quickly promoted at the Peddie Institute, first to assistant principal in 1886, then to principal in 1889. During his time at the Peddie Institute he completely reorganised the Mathematics Department. However, despite his success or perhaps because of it, he decided to aim higher. Gilbert Bliss writes :-
He had married Miss Mary L Davis, the instructor in music at Peddie, in 1885, and she sympathized with and encouraged his desire to enter the field of university mathematical work, even though such a course meant a serious sacrifice for them for some time to come. So in 1892 Slaught accepted a two-year appointment to one of the first three fellowships awarded by the Department of Mathematics at the University of Chicago, which was just then opening its doors.
Chicago had not been Slaught's first choice, for he had planned to undertake research for his doctorate at Johns Hopkins University and had applied for a fellowship. However, Frederick Taylor Gates, an advisor to John D Rockefeller, knew Slaught because of his efforts to gain funding for the Peddie Institute and, when he learnt that Slaught was applying to study for a Ph.D. in mathematics, he arranged for him to be interviewed by William Rainey Harper, the first President of the newly founded University of Chicago :-
President Harper with characteristic decisiveness offered Slaught a two-year fellowship with a guarantee of extra summer quarter teaching to help out with his finances, and Slaught accepted. He thus became one of the first three fellows in the department of mathematics at the University of Chicago.
After two years of research at Chicago, his fellowship ended and he was appointed onto the teaching staff. He did not complete his doctorate until 1898 because of the high teaching load that he had. His research had been supervised by Eliakim Moore and he was awarded his doctorate for a thesis entitled The Cross Ratio Group of 120 Quadratic Cremona Transformations of the Plane. Slaught soon received promotion at the University of Chicago. In 1900 he was made an assistant professor, them associate professor in 1908 and full professor in 1913. Slaught remained at Chicago for the rest of his career, retiring from his chair in 1931.
Let us quote from William David Reeve about Slaught's abilities as a teacher :-
Professor Slaught's great contribution was as a teacher and as an inspiration to his students, many of whom either were teachers or later became teachers. Many students who had studied calculus before, learned what the subject really meant in Professor Slaught's class. He was a kindly, intensely human, and understanding teacher who knew how to sympathize with ordinary students as well as to select those whom he wished to spur on to more advanced work. Many students of his will never forget the pleasant hours spent at his home with his wife and daughter Katherine at the teas on Sunday afternoons. His influence on the students at the University of Chicago both inside and outside of class was invaluable.
During 1902-3 Slaught travelled in Europe attending lectures by the leading mathematicians. Perhaps he felt that he could never achieve the depth of research he was exposed to at this time for, after a worrying time of indecision, he decided that he was not cut out for a research career but could give most to the world of mathematics by concentrating on teaching. On his return in 1903, the Central Association of Science and Mathematics Teachers was beginning to become active and he at once joined the organization and became one of its most active supporters. He was later made one of the few honorary life members of the Association.
After seeking Leonard E Dickson's advice on the best way to serve the mathematical community, he accepted Dickson's suggestion of becoming co-editor of the American Mathematical Monthly. He served as an editor of the Monthly from 1907 to 1937. In 1913 he became Managing Editor and continued to hold that position until 1918 when the post was renamed Editor-in-Chief. He was then Editor-in-Chief 1916-18 :-
Slaught, probably more than any other person, had the conviction that more must be done for the average teacher of mathematics and more must be done within the field of collegiate mathematics. As far back as 1912 the question was raised as to the possibility of having the American Mathematical Society extend its scope so as to include the publication of the Monthly. The proposition took a more definite shape, under Slaught's impetus, at the April 1914 meeting of the Chicago Section of the Society.
William DeWeese Cairns, who was President of the Mathematical Association of America in 1943-44, writes in  of his:-
... grateful tribute to [Slaught] for the intelligent direction which he gave to those whom he selected as his assistants. He moved consistently toward bringing as many different people as possible into active work for the 'Monthly' and the Association; this is strikingly verified if one merely glances at the extensive lists of associate editors of the 'Monthly' and officers of the Association. He was remarkable in his power of spying out new men and women of promise and of guiding them into enthusiastic service.
Slaught also became active in the organisation of the Mathematical Association of America and served as its President in 1919. He also strongly supported the Chicago section of the American Mathematical Society serving as its secretary from 1906 to 1916. The third annual meeting of the Association was held, in conjunction with a meeting of the American Mathematical Society, in Chicago in December 1918. Slaught was chairman of the local organising committee. In September 1919 a joint meeting of the Mathematical Association of America, the American Mathematical Society and the American Astronomical Society was held at the University of Michigan. Slaught acted as toastmaster at a joint dinner for all three societies.
He also played a major role in founding the National Council of Teachers of Mathematics in 1920 :-
Always sympathetic with progress in the teaching of secondary school mathematics, he continued, in his busy existence, to hearten and to advise. The Council paid him the high honour in January 1937 of electing him honorary president for life. Much to his own delight and to the later pleasure of the Council members, he was enabled in his own home in February 1937 to make a disk record of a speech to be reproduced at the annual meeting of the Council at the Hotel Stevens in Chicago.
We can see from Slaught's work for many societies and associations which were interested in secondary school teaching that he had a strong interest in that area. In fact he wrote many articles about secondary school teaching of mathematics.
We give some brief extracts from some of these articles at THIS LINK.
He also wrote many textbooks at school and undergraduate level. For example: (with Nels Johann Lennes) High-School Algebra. Elementary Course (1907), (with Nels Johann Lennes) High-School Algebra. Advanced Course (1908), (with Nels Johann Lennes) Plane Geometry with Problems and Applications (1909), (with Nels Johann Lennes) First Principles of Algebra (1911), (with Nels Johann Lennes) Solid Geometry: With Problems and Applications (1911), (with Ernest Julius Wilczynski) Plane Trigonometry and Applications (1914), (with Ernest Julius Wilczynski) Logarithmic and Trigonometric Tables (1914), and (with Ernest Julius Wilczynski) College Algebra with Applications (1916).
For brief extracts of reviews of these and other texts by Slaught, see THIS LINK.
Bliss, in , describes Slaught as:-
... one of the men most widely known by teachers and students of mathematics... His lifelong devotion to... the promotion of the study of mathematics, his skill as a teacher, his effective leadership in the mathematical organizations which he sponsored, and his influence with teachers of mathematics the country over, were remarkable.
Samuel Thomas Sanders, professor at the Southwestern Louisiana Institute, writes :-
We first sat in his classes as a student in the spring of 1908. From the very beginning, we were impressed with the dynamic humanness of the man. But little study of his teaching was needed to show that his power as a teacher of mathematics came essentially from the indivisible union in his nature of two things: (a) a profound love of mathematics, (b) an equally profound interest in his fellows, especially young people. These two qualities could scarcely have been consistent with any programs he might originally have entertained for extensive mathematical research. Indeed, the cause of mathematics in America would probably have suffered had he chosen to confine his energies to research. ... Professor Slaught's manner was entirely unpretentious and free from the slightest affectation. Wholesome humour was one of his marked characteristics, and was reflected in his laugh. That laugh, utterly free from sarcasm or rancour, was so hearty, so sincere, so warm with the spirit of good-fellowship that quite every one to whom he might talk, whether in casual conversation or sitting as a student of one of his classes, could not avoid thinking of him more as a good pal than as a professor of mathematics.
Let us end this biography of Slaught by quoting from Ellen Grassman :-
The following tributes were given at the time of his death in 1937. "His was a rare spirit, a great heart, a rich personality, a generous soul," said Nelson L Greene. "He has thus for many years been influential in the affairs of the most important of the mathematical associations of our country." This is a statement from 'Science'. "He had an unselfish interest in the problems and personalities of those with whom he came in contact," was another statement made in the 'American Mathematical Monthly'.
Article by: J J O'Connor and E F Robertson