I recommend this site. There is much of interest in addition to the lecture related to this thread.
"Lincoln and Shakespeare
Stephen Dickey, an award-winning senior lecturer at UCLA, has often been on the faculty of Folger Shakespeare Library's NEH-funded Teaching Shakespeare Institute, which brings high school teachers from around the country to Washington, DC, for a month of intensive study. In the 2006 session, participants studied four plays, including Macbeth and Julius Caesar. This portion of a lecture by Dickey during the session explores President Lincoln's knowledge of Shakespeare and his special affinity for Macbeth."
http://www.shakespeareinamericanlife.org...speare.cfm