Theodore Roosevelt by John Singer Sargent
Today is “Presidents Day” here in the U.S. — originally “Washington’s Birthday”, but now an all-purpose Washington and Lincoln birthday holiday, marked primarily by aggressively advertised sales of mattresses and cars. (Maybe that says something about U.S. presidents, I don’t know.)
Though perhaps not one of Sargent’s most memorable paintings, this portrait of the 26th U.S. president certainly counts as one of the best official presidential portraits. For a full array of official portraits, see this slide show feature on whitehouse.gov.
There is fairly large image of this painting on Wikimedia Commons.