1
You may fool all the people some of the time, you can even fool some of the people all the time, but you can't fool all of the people all the time
Attribution contested
No contemporaneous record of Lincoln saying this survives. It first appears in recollections published decades after his death, and has also been credited to P. T. Barnum. Even the wording is unstable: this is McClure's 1901 text, which differs from the version usually quoted today. Treat the phrasing as the compiler's, not Lincoln's.