Prior to his 1860 address at the Cooper Institute (presently known as Cooper Union) Lincoln "was known in the East chiefly as a rather obscure western lawyer who had gained some prestige a little over a year earlier in the debates with Douglas during the Illinois senatorial contest. The day after the address Horace Greely's NEW YORK TRIBUNE remarked:
"No man ever before made such an impression on his first appeal to a New York audience".
"This speech put within Lincoln's grasp a chance for the Presidency".
Attached, you will find his very powerful conclusion to the address.