No U.S. President was ever assissinated before Lincoln. Jackson's case was a failure and the man who tried was beaten badly by Jackson and deemed insane. Somebody was always trying to kill Jackson, president or not, he had the scars to prove it, so I really don't think his counts. Up until Lincoln the thought of killing a sitting president for political motivations was novel. Security for presidents was novel. Lincoln had to hire a private security firm because the government didn't have one. The security for Lincoln was so lax that Booth got in and got out without anybody stopping him, in a city full of military. General Grant had more security for him than Lincoln did. The Secret Service didn't get the job of protecting the President until I believe the beginning of the 20th Century, I know it was after the Civil War.

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David Upton