This is one of those writeups that I hope will be surpassed soon... Please do your best to make it redundant.
Russell S. Ohl was born in Pennsylvania in January of 1898. At age 16, he entered Pennsylvania State College (now Pennsylvania State University), where he took a degree in electrical engineering*. After a stint in the army (this was during WWI), he floated from job to job, teaching briefly at University of Colorado, and working for Westinghouse and AT&T, among others.
He did all kinds of stuff involving advancements to radio transmitting, vacuum tubes, and other electronical endeavours, most of which was is now outdated and forgotten, although quite important. The one thing that he is still remembered for is his discovery of the pure silicon photocell in 1940. While working for AT&T he discovered that a piece of pure silicon placed between two wires would block the current, until a light was shown on it**. This is usually considered the starting point for the development of the transistor.
William Shockley, John Bardeen and Walter Brattain were given the task of making this into something useful for commercial enterprise, preferably a solid-state replacement for the telephone relay in switching stations. (You may recognize these names -- they ended up winning a prize for their work with transistors).
I don't know what happened to Ohl -- maybe he's still alive. The one good source of information on him I've found on the web is:
* I am not positive of this. I would not have included it unless I was pretty sure, but his degree may not have been in electrical engineering, but in a closely related subject.
** That was the simple explanation -- here's a slightly more complicated one: He treated a block of silicone so that it had positive ('p' type) and negative ('n' type) zones. When a light was shown on the line dividing the two zones a current was generated, and this additional current permitted the circuit to close. This change of an 'insulator' to a 'conductor' by way of an application of a small charge is the basis of transistors.