I realize this is what you've read over and over in pro-Confederate sources, but it is simply false. Lincoln was trying to avoid using force because he didn't want a war, and the Radicals were increasingly voicing the suspicion, even on the Senate floor, that Lincoln was willing to let the Deep South leave in peace.
Lincoln showed no interest in sending a naval convoy to Sumter for any reason--until Davis idiotically forced his hand by cutting off the garrison's food supply. Once news of the cutoff reached the North, Northern pro-coercion newspapers erupted with screams about the "starving garrison." Even then, Lincoln strove to make the convoy as inoffensive and unprovocative as possible.
If Lincoln harbored any malice toward the South, he certainly didn't show it when he established merciful, modest Reconstruction terms for Louisiana in 1863, well before the war ended. Nor did he show any anti-Southern malice when the South surrendered. He told Grant to give lenient, generous surrender terms, which Grant did.
Lincoln's moderate and forgiving Reconstruction terms were trashed by the Radical Republicans after Lincoln died and after they gained control over Reconstruction.
The Deep South states blundered badly in refusing to honor the 1860 election results, which they were required to do by the Constitution. If they had waited and given Lincoln a chance to see how he would govern, and if Lincoln had proceeded to start persecuting the South, then the Southern states would have had valid reason to leave the Union. But they didn't even give Lincoln a chance.
