Abraham Lincoln's 1858 speech to the Illinois Republican Convention that nominated him for a seat on the United States Senate is available here. This speech is known as the "House Divided Speech" because Lincoln used that phrase to express his views about the coming crisis between the North and the South.
The text of the Thirteenth Amendment to the United States Constitution, which abolished slavery.
Abraham Lincoln's address to Congress, 4 July 1861, in which he called for huge numbers of troops to fight the war.
Abraham Lincoln's proclamation that suspended the writ of habeas corpus, September 24, 1862.
Chief Justice Roger Taney's (the same judge who presided over the Dred Scott Case) ruling in Ex parte Merryman, which stated that Lincoln's suspension of habeas corpus was illegal.