Main Entry: mournful
        Pronunciation: 'mOrn-f&l, 'morn-
        Function: adjective
        Date: 15th century
        1 : expressing sorrow : SORROWFUL
        2 : full of sorrow : SAD
        3 : causing sorrow or melancholy : GLOOMY
 

      Walt Whitman is describing the American people's reaction to Abraham Lincoln's assassination.  Everyone is at a loss, shocked, and devastated.  They all grieve and feel a pit of sorrow for the death of their captain and father.  Abraham Lincoln was shot in the head by John Wilkes Booth on April 14, 1865, at around 10:15pm, in the Ford's Theater.

     For more information on Abraham Lincoln's Assassination visit:
     http://home.att.net/~rjnorton/Lincoln75.html
     http://www.loc.gov/exhibits/treasures/trm012.html