The beardless portrait from Harper's Weekly, taken from a photograph by Matthew Brady, appeared the day after his election as the sixteenth president. At the time, Harper's enjoyed a very large circulation and the youthful and handsome image did much to promote Lincoln's popularity. This image probably introduced his visage to more Americans than any other.
Throughout the civil war Lincoln appeared on magazines, and, as politicians are today, was often the brunt of satire and caricature.
Here's my favorite, currently on loan to the Newseum in Washington, though there are dozens of great examples scattered about in such obscure and rare titles as Phunny Phellow, Comic Monthly and Punchinello, to name only a few.
The best images from the time of his assassination appeared in the second most widely circulated news periodical Frank Leslie's Illustrated Newspaper. Civil War issues of Leslie's are harder to find and thus a bit more expensive than Harper's Weekly.
Lincoln remained a frequent subject of periodicals after his death. Here is a rare "campaign paper" issued in conjunction with the 1872 election.
Happy 200th Mr. President.