New York: American Telephone and Telegraph Company 1948. First Edition. July: 379-592 pages, 8vo. ; October: 593-751,  pages, 8vo. Both original blue printed wrappers. Both housed in a custom leather clamshell case. July issue has stamps "Property of the Telephone Systems Training Section" on front wrapper and first page. Spine slanted and lightly sunned. A better than average copy. October issue has pencilled note at top of front wrapper, and is creased in the upper right corner (increasingly obvious as the issue progresses). Creases to rear cover. Otherwise clean. The Shannon article is in 2 parts, found on pp 379-423 (July) and 623-656 (October). Very Good. Wraps. 
Claude Shannon is credited with founding the field of information theory. Previous to the work done in this paper, the noise found on transmission lines was treated fundamentally differently. The previous solution was to "shout louder" so that the signal could be heard over the noise. With the introduction of the "bit" or binary digit, and the practical introduction of coding theory by Hamming and others, the start of modern transmission technologies were born. Without Shannon's work, the internet as we know it would not exist.
"In this paper it was shown that all information sources - telegraph keys, people speaking, television cameras and so on - have a 'source rate' associated with them which can be meausred in bits per second...The information can be transmitted over the channel if and only if the source rate does not exceed the channel capacity...This work on communication is generally considered to be Shannon's most important scientific contribution...Few other works of this century have had greater impact on science and engineering. By this landmark paper and his several subsequent papers on information theory he has altered most profoundly all aspects of communication theory and practice." (Shannon Collected Papers p. xiii).
"What began as a study of transmission over telegraph lines [ by Nyquist and Hartley ... ] was developed by Shannon into a general theory of communication applicable to telegraph, telephone, radio, television, and computing machines - in fact, to any system, physical or biological, in which information is being transferred or manipulated through time or space" (Aspray, 1985, pp. 119-22) Shannon's paper was also responsible for introducting the term 'bit' (for binary digit) into the published literature, and for giving the term it's current meaning..." (Origins of Cyberspace 880)
In this fundamentally important paper, Shannon laid the foundation for much of today's interconnected world. Finding these papers in decent original wrappers is getting more difficult. Bound copies are more available.
Shannon, Collected Papers, #37. Origins of Cyberspace 880. Aspray, 1985, pp119-22.