The source of this file is the United States Senate Historical Office. I got permission (to post this photo on Wikipedia) over the phone, in person, from Ms. Heather Moore, the United States Senate Photo Historian. Ms. Moore can be reached at 202-224-6900. The url contact page for Ms. Moore is http://bioguide.congress.gov/copyright.htm. Ms. Moore said that the photo is in the public domain, but that credit for the photo does need to be posted as "credited to the U.S. Senate Historical Office." The URL where this photo was retrieved from is: http://bioguide.congress.gov/scripts/biodisplay.pl?index=M000486