Lincoln was called on to handle both the political and military aspects of the Civil War, facing challenges in both spheres. As commander-in-chief, he ordered the suspension of the constitutionally-protected right to habeas corpus in the state of Maryland in order to suppress Confederate sympathizers. Responding to criticism of Grant after Shiloh, Lincoln had said, 'I can't spare this man. He fights.' In March 1864, Grant was summoned to Washington to succeed Halleck as general-in-chief, while Halleck took on the role of chief-of-staff. Lincoln refused to allow any negotiation with the Confederacy as a coequal; his sole objective was an agreement to end the fighting and the meetings produced no results.Grant ground down the Confederate army across several months of trench warfare. Due to the city's important location, the fall of Petersburg would likely lead to the fall of Richmond, but Grant feared that Lee would decide to move South and link up with other Confederate armies.
Halleck
Halleck