The 275,000+ texts were taken from the TIME Archive, which is freely available online. I cannot redistribute these texts, but you may wish to download (a portion of) them yourself.
This Excel spreadsheet contains complete information on the texts used in the corpus (article ID, year, date, title, author, section, and number of words). The [ID] column refers to the [t] value in the URL in the [title] column of the Keyword in Context display. For example, if the URL is http://corpus.byu.edu/time/x4.asp?t=824347&ID=39942022, then the [textID] is , and this corresponds to [The Big Money] (Sep 3, 1956) in the spreadsheet.