<P> Despite recent setbacks in the Western Theater of the war, the June 1864 National Union National Convention nominated Lincoln for president . Though Hamlin hoped to be re-nominated as vice president, the convention instead nominated Andrew Johnson, the military governor of Tennessee . Lincoln had refused to weigh in on his preferred running mate, and the convention chose to nominate Johnson, a Southern War Democrat, in order to boost the party's appeal to Unionists of both parties . The party platform called for the unconditional surrender of the Confederacy, and also endorsed open immigration policies, the construction of a transcontinental railroad, and the establishment of a national currency . </P> <P> By August, Republicans across the country were experiencing feelings of extreme anxiety, fearing that Lincoln would be defeated . The outlook was so grim that Thurlow Weed told the president directly that his "re-election was an impossibility ." Acknowledging this, Lincoln wrote and signed a pledge that, if he should lose the election, he would nonetheless defeat the Confederacy by an all - out military effort before turning over the White House: </P> <P> This morning, as for some days past, it seems exceedingly probable that this Administration will not be re-elected . Then it will be my duty to so co-operate with the President elect, as to save the Union between the election and the inauguration; as he will have secured his election on such ground that he cannot possibly save it afterwards . </P> <P> Lincoln's re-election prospects grew brighter after the Union Navy seized Mobile Bay in late August and General Sherman captured Atlanta a few weeks later . These victories relieved Republicans' defeatist anxieties, energized the Union - Republican alliance, and helped to restore popular support for the administration's war strategy . With these victories, the underlying disarray within the Democratic Party came to the surface . The 1864 Democratic National Convention met at the end of August, nominating General George McClellan as their presidential candidate . The divided Democrats adopted a platform calling for peace with the Confederacy, but McClellan himself favored continuing the war . McClellan agonized over accepting the nomination, but after the Union victory in Atlanta, he accepted the nomination with a public letter . </P>

The united states was involved in which conflict during abraham lincoln’s 1864 address