Founded by Knute Oscar "K.O." Lee (1862-1934), the K.O.Lee grinding concern was based in Aberdeen, South Dakota. At first the business had nothing to do with machine tools, but sold and serviced agricultural machinery including steam engines, gasoline tractors, threshing machines and plows. In 1922 a German immigrant machinist-engineer, Theodore Purnis, joined the company, his job being to train machinists in the repair shop that handled the rebuilding of internal combustion engines. During the 1920s, in order to assist the machine shop, Mr. Purnis developed several small grinding machines and associated tools and, in 1926, was registered as the co-inventor of a replacement valve seat for cylinder heads. At around the same time the company became involved in the twine binder market, the raw material being imported from Europe, where it was produced in a number of countries, and then sold throughout Montana, South Dakota, North Dakota, Nebraska, Iowa and Minnesota. With the start of WW2, in 1939, supplies of the twine became unavailable and the company concentrated instead on their embryonic tool manufacturing business. So successful was this enterprise that that, in 1941, a move was made to a 35,000 square foot factory on a newly-built industrial park, the company re-branding itself as the "K.O. Lee Company". Today, now owned by LeBlond, a small range of machines - together with a spares service for older models, continues to be offered. However, in earlier years the company range was very much wider and including numerous variation on a common theme, together with a wide range of useful accessories.
Carried on a substantial base, all models of K.O.Lee tool grinder had their work head carried on top of an elevating, 4-inch diameter column situated at the rear of the machine - the able to be rotated through 360° and elevated  6.75". However,  many other makers of tool and cutter grinder preferred raise the whole knee assembly instead, as found, for example, on the American Greenfield and unusual LeBlond, both these makes being current from the first decade of the 20th century. However, the rise-and-fall column design was popular, and the arrangement can be found on a number of machines from other makers models including the original vintage Jones and Shipman and later Model 310, the Bauerle, Cincinnati and Union/Harrison as well as amateur examples from the English makers Perfecto, Quorn and Stent.
As was common on this type of machine from almost all makers, the main table was topped by a sub table that could be set over at a precise angle under the control of setting screws and able to carry, located in a single, centrally-positioned T-slot, accessories that allowed cylindrical, internal, centreless and surface grinding to be undertaken. The main table also swivelled, against a graduated scale, the total rotational movement being 225°. One option offered by K.O.Lee (and not commonly found on other makes) was a screw-driven fine-feed mechanism for the table's longitudinal travel. 
Of accurate but essential simple construction - with the usual hand operation of feeds as found on similar machines from other makers - K.O.Lee were unusual in offering a hydraulic table feed conversion for the Models BA900 and B2000, this fitting improving the machines' abilities when employed for cylindrical and surface grinding.
Reproduced below - and on following pages -  is a catalog that shows the range of K.O.Lee machines and accessories as manufactured during the late 1960s - the extent and types offered being similar in both the preceding and subsequent decades.
Tool and Cutter grinders fall into three broad categories: (1) special types of limited functionality used, for example, for the sharpening of "D bits" and other cutters used by pantograph engravers; (2) standard machines for the grinding of the such ordinary items as end mills, slot drills, side-and-face cutters and slab mills and (3) the more versatile "universal" machines, such as the Dowling, where the design allowed other forms of grinding to be performed. When considering the purchase of a tool and cutter grinder be sure that it does not fall into category (1) - check that it has a similar range of movements and settings available on standard machines such as the Clarkson and Quorn. However, should you decide on a more versatile example, compare its design and functionality to the Dowling, LeBlond and Jones and Shipman Model 310 and 1014. While tool and cutter grinders are a most useful addition to any workshop, do beware of buying one without accessories; although some limited work is possible on a basic machine, to exploit it fully, rather more is required. Installed in a professional workshop a typical example might well be complete with a number of useful extras including: a radial grinding attachment; collets; a universal grinding head; universal (double swivel) work-holding fixture; a self-contained, table-mounted motor-driven workhead; sensitive workhead and a selection of precision, very slightly tapered arbors to hold workpieces..