CCOT: Lincoln's Changing Interpretation Thesis

After reading and interpreting the following excerpts, write a complex thesis statement to answer the question below.

Apprehension seems to exist among the people of the Southern States that by the accession of a Republican Administration their property and their peace and personal security are to be endangered.  There has never been any reasonable cause for such apprehension.  Indeed, the most ample evidence to the contrary has all the while existed and been open to their inspection.  It is found in nearly all the published speeches of him who now addresses you.  I do but quote from one of those speeches when I declare that-- 
I have no purpose, directly or indirectly, to interfere with the institution of slavery in the States where it exists. I believe I have no lawful right to do so, and I have no inclination to do so. 
Physically speaking, we cannot separate.  We cannot remove our respective sections from each other nor build an impassable wall between them.  A husband and wife may be divorced and go out of the presence and beyond the reach of each other, but the different parts of our country cannot do this.  They cannot but remain face to face, and intercourse, either amicable or hostile, must continue between them. 
We are not enemies, but friends. We must not be enemies. Though passion may have strained it must not break our bonds of affection. The mystic chords of memory, stretching from every battlefield and patriot grave to every living heart and hearthstone all over this broad land, will yet swell the chorus of the Union, when again touched, as surely they will be, by the better angels of our nature.
Document 1: Excerpts from Abraham Lincoln’s First Inaugural Address, March 4, 1861

That on the first day of January, in the year of our Lord one thousand eight hundred and sixty-three, all persons held as slaves within any State or designated part of a State, the people whereof shall then be in rebellion against the United States, shall be then, thenceforward, and forever free;
And I further declare and make known, that such persons of suitable condition, will be received into the armed service of the United States to garrison forts, positions, stations, and other places, and to man vessels of all sorts in said service.
And upon this act, sincerely believed to be an act of justice, warranted by the Constitution, upon military necessity, I invoke the considerate judgment of mankind, and the gracious favor of Almighty God. 
Document 2: Excerpts from the Emancipation Proclamation, 1863

[1] Fourscore and seven years ago our fathers brought forth on this continent, a new nation, conceived in Liberty, and dedicated to the proposition that all men are created equal.

[2] Now we are engaged in a great civil war, testing whether that nation, or any nation so conceived and so dedicated, can long endure. We are met on a great battle-field of that war. We have come to dedicate a portion of that field, as a final resting place for those who here gave their lives that that nation might live. It is altogether fitting and proper that we should do this.

[3] But, in a larger sense, we can not dedicate-we can not consecrate-we can not hallow-this ground. The brave men, living and dead, who struggled here, have consecrated it, far above our poor power to add or detract. The world will little note, nor long remember what we say here, but it can never forget what they did here. It is for us the living, rather, to be dedicated here to the unfinished work which they who fought here have thus far so nobly advanced. It is rather for us to be here dedicated to the great task remaining before us-that from these honored dead we take increased devotion to that cause for which they gave the last full measure of devotion-that we here highly resolve that these dead shall not have died in vain-that this nation, under God, shall have a new birth of freedom-and that government of the people, by the people, for the people shall not perish from the earth.
Document 3: ABRAHAM LINCOLN, “GETTYSBURG ADDRESS” (19 NOVEMBER 1863)

On the occasion corresponding to this four years ago all thoughts were anxiously directed to an impending civil war. All dreaded it, all sought to avert it. While the inaugural speech was being delivered from this place, devoted altogether to saving the Union without war, insurgent agents were in the city seeking to destroy it without war--seeking to dissolve the Union and divide effects by negotiation. Both parties deprecated war, but one of them would make war rather than let the nation survive, and the other would accept war rather than let it perish, and the war came.

One-eighth of the whole population were colored slaves, not distributed generally over the Union, but localized in the southern part of it. These slaves constituted a peculiar and powerful interest. All knew that this interest was somehow the cause of the war. To strengthen, perpetuate, and extend this interest was the object for which the insurgents would rend the Union even by war, while the government claimed no right to do more than to restrict the territorial enlargement of it. 

With malice toward none, with charity for all, with firmness in the right as God gives us to see the right, let us strive on to finish the work we are in, to bind up the nation's wounds, to care for him who shall have borne the battle and for his widow and his orphan, to do all which may achieve and cherish a just and lasting peace among ourselves and with all nations.
Document 4: Excerpt from Lincoln’s Second Inaugural Address, March 1865

Write a complex thesis for this question: To what extent did the issues faced during Abraham Lincoln’s presidency maintain continuity and foster change?