Lincoln set off for New York from Springfield in late February. His original itinerary was to speak in Brooklyn and then travel to Exeter. Abraham Lincoln’s February 27, 1860, speech at the Cooper Union Institute in New York City is now unanimously characterized as the event that led to his presidential nomination by spreading his political genius beyond the Midwest. Or, as one historian more simply, yet very aptly, states, the speech was “the most pivotal public appearance of [Lincoln’s] career.” In it, he explored the history of American slavery going back to the Founders’ original thoughts and beliefs on the subject and showed not only that slavery’s national extension was wrong but also that it—plus the Dred Scott decision that allowed such nationalization—was politically espoused on “assumed historical facts which were not really true.” The speech was such a great success that speaking request deluged him during his entire eastern trip. Immediately after completing his Cooper Union speech, he was beseeched to speak to Providence, Rhode Island, the very next day; while in Providence, he received an invitation to speak at Exeter during his visit to his son. Robert also received a letter that day from the Dover, New Hampshire, Republican Committee, asking if his father could be persuaded to speak in that city whole in the area. Robert responded that he would give the letter to his father, who would answer it himself, “though I have no doubt he will be happy to comply with your kind invitation should his time permit.” Emissaries from the Dover Committee then met Lincoln on his arrival to Exeter and secured a promised speech from him for March 2.
– Giant in the Shadows The Life of Robert T. Lincoln by Jason Emerson