History of Privacy
The concept of privacy in American law can be traced to the article The Right to Privacy, written by Samuel Warren and Louis Brandeis in 1890. It is interesting to note that the catalyst for this article was technology. From the article: Instantaneous photographs and newspaper enterprise have invaded the sacred precincts of private and domestic life; and numerous mechanical devices threaten to make good the prediction that "what is whispered in the closet shall be proclaimed from the house-tops."
This short episode (8 minutes) from PBS includes more on the history of electronic privacy in the United States.