Lincoln did not, nor did Edward Everett, the main speaker at the dedication of Gettysburg. Both read from the written page. In fact Lincoln did not finish writing that speech until late the evening before the day he actually delivered it.
Lincoln did write his own speeches generally though. Lucky for us too as he is arguably one on, if not perhaps the very best, writers in the English language.... no disrespect to either The Bard or Mr. Churchill. There is some question as to whether or not he actually wrote the famous condolence letter to Mrs. Bixby but there is no evidence either way and the opinions against his being the author are pretty thin IMO. But then I am biased probably and an unabashed fan of the man.
Just as a short example of the man's ability to assemble the same words we all may use and have access to:
"My friends, no one, not in my situation, can appreciate my feeling of sadness at this parting. To this place, and the kindness of these people, I owe everything. Here I have lived a quarter of a century, and have passed from a young to an old man. Here my children have been born, and one is buried. I now leave, not knowing when, or whether ever, I may return, with a task before me greater than that which rested upon Washington. Without the assistance of the Divine Being who ever attended him, I cannot succeed. With that assistance I cannot fail. Trusting in Him who can go with me, and remain with you, and be everywhere for good, let us confidently hope that all will yet be well. To His care commending you, as I hope in your prayers you will commend me, I bid you an affectionate farewell."
-A. Lincoln Springfield, Illinois (his home town) 11 Feb 1861 before he boarded the train that would take him to Washington, D.C. and the presidency.
Brian
Some people actually memorised whole speeches back in those days.