Remembering Abraham Lincoln

Today -- April 14, 2015 -- marks the 150th birthday of the assassination of President Abraham Lincoln (1809 - 1865) and April 15 is the date on which he died. Lincoln loved poetry and trained his reasoning with Euclid's geometry.  Here is a brief sample of his own poetry (found -- along with other samples -- at PoetryFoundation.org).

       Abraham Lincoln     by Abraham Lincoln

       Abraham Lincoln
       his hand and pen
       he will be good but
       god knows When

From my copy of Walt Whitman's Leaves of Grass (Signet Classics, 1955), from the section "Memories of Lincoln," I have copied these well-known and thoughtful (and non-mathematical) lines:

This Dust Was Once the Man     by Walt Whitman ( 1819-1892)

THIS dust was once the Man,   
Gentle, plain, just and resolute—under whose cautious hand,   
Against the foulest crime in history known in any land or age,   
Was saved the Union of These States.