What a silly question. You should study up more on how they spoke during that era. They did not use the term "Dude". Lincoln was a lawyer. he spoke in educated words and phrases.
Probably false, but would be funny. Because as you may have heard your friends say that a camel's penis is actually called a 'dude'. So i don't think he would have been calling or saying 'Camel's penis' all the time