PREVIEW: ##Civil War: Comment by colleague and author, Patrick O'Donnell, author of THE UNVANQUISHED, of what is known and unknown re the scale of the plot against the Lincoln Cabinet by the Confederate Secret Service -- and the role Mosby's Rangers may h

PREVIEW: ##Civil War: Comment by colleague and author, Patrick O'Donnell, author of THE UNVANQUISHED, of what is known and unknown re the scale of the plot against the Lincoln Cabinet by the Confederate Secret Service -- and the role Mosby's Rangers may have played in the plan that led to the assassination of Lincoln and the severe woundng of Seward.  More details tonight..

1865 Lincoln in Richmond, April 4, 1865