"It is surely safe to assume that the  framers of the original Constitution and the  members of the Congress which framed the amendments thereto, taken together, do certainly include those who may be fairly called 'our fathers who framed the [g]overnment under which we live'. And so assuming, I defy any man to show that any one of them ever, in his whole life, declared that, in his understanding, any proper division of local from federal authority, or any part of the Constitution, forbade the [federal government] to control as to slavery in the federal territories." (Abraham Lincoln)
"[O]ne of the most happiest and most convincing political arguments ever made in this [city] ... No man ever made such an impression on his first appeal to a [New York] audience." (Horace Greeley)
After the Lincoln-Douglas debates made Lincoln a nationally recognized politician, Illinois papers began to mention Lincoln as a Republican candidate for president in 1859. Lincoln was humbled, though a bit dumbfounded. He thought himself more suited for the Senate, where he could orate and discuss ideas. Moreover, there were Republicans of much greater national prominence on the East Coast, particularly William Seward.
Lacking any administrative experience, Lincoln wasn't sure he would enjoy being president, but even being considered was a great honor, and he quietly thought the idea over. In fact, Lincoln was still not considered a real option for the nomination until he delivered a speech at New York City's Cooper Union in February, 1860, just a few months before the Republicans' convention in May.