Who knew honest Abe Lincoln was a fierce courtroom litigator? ABC News chief legal correspondent Dan Abrams takes Salon back to 1859 and into a murder trial courtroom with Lincoln, the lawyer, nine months before he got the Republican nomination. Abrams' new book "Lincoln's Last Trial: The Murder Case That Propelled Him to the Presidency" unearths the only transcript of Lincoln's law career ever found, discovered miraculously in a garage in 1989.

Abrams relates lessons from Lincoln's courtroom to today as U.S. Special Counsel Robert Mueller's investigation presses on and the idea of President Trump's assessment of truth is analyzed and questioned daily. Are factual inaccuracies Trump's speeches and tweets lies or just non-truthful statements? Is there a difference? "It can't be every time the president says something that is not accurate, it's a lie," Abrams told SalonTV. "I think to say it's a lie, there has to be... I don't want to say proof but, you have to believe that he knows it's not true. He knows it's not true and he's saying it. In some of these cases, it's possible that people around him told him something that isn't accurate, right?"