What were Lincoln's motives & the effects of those actions during the Civil War. Was he more conservative or revolutionary?

As stated, Lincoln's motives were to preserve the United States, and he did so, even at times acting illegally.  The sectionalism that had been growing since the founding of the original colonies finally came to conflict in the 1860's; slavery was but a minor component to the differences between North and South.  However, Lincoln brilliantly used the issue of slavery in the Emancipation Proclamation by "freeing all slaves in areas in rebellion against the United States" which didn't eliminate slavery, but allowed the Union Army to act as the liberator of the oppressed.  By Lincoln actively stating the North's opposition to slavery (and this was done in 1863, during the middle of the war) he had also hoped to make this a foreign policy directive in keeping Great Britain out of the war on the Southern side.  Since Britain had banished slavery in her confines in the 1830s, they could not openly recognize the Confederacy.  Lincoln's gambit worked.

However, the Constitution specifies how areas may join the United States; it does not specify how areas may leave the United States.  Had the Founders inserted that provision, the whole war may have been avoided.  Lincoln did not preserve the Constitution; he preserved the Union by conquering the South.