I recently discovered an interesting blog post from David Parker from a few years back:

On September 2, 1858, speaking in Clinton, Illinois, during the famous Lincoln-Douglas debates, Abraham Lincoln made one of his most famous statements: “You can fool all the people some of the time and some of the people all the time, but you cannot fool all the people all the time.” Or maybe he said it a couple years earlier, at the 1856 Republican Convention.

Actually, we don’t know when he said it, or even if he said it at all. The above attributions were offered nearly a half century after the fact, and are generally considered unreliable. (Thomas Schwartz, former historian of the Abraham Lincoln Presidential Museum, called the claims “tenuous,” and Don and Virginia Fehrenbacher, authors of Recollected Words of Abraham Lincoln, gave the claims a grade of “D.”)

Read the whole thing.