What is the Washington Post article "Fake news? That’s a very old story" about?

The article "Fake news? That's a very old story." is an opinion piece written by Robert Parkinson. Parkinson is a history professor at Binghampton University and the author of "The Common Cause," which describes the ways racism and prejudiced were used to convince people to join the revolutionary side during the American Revolution. 
Parkinson's article points out that the fake news that helped Trump win the Presidency has been a part of American history as far back as the Revolutionary War. There is evidence that John Adams and William Livingston both wrote fake articles meant to incite public outrage against the king. Benjamin Franklin wrote a fake article that claimed Native Americans working for Britain scalped 700 people, including children and infants. This article didn't come out until 1782, so it didn't have an effect on the war, but it probably soured public opinion of Native Americans.
Thirty years later, during the war of 1812, Benjamin Franklin's false claims of mass scalpings were reintroduced through several other newspapers. This solidified the idea that Native Americans were the real enemy, which would, of course, help justify the abuse they'd receive later on. This brings us to the point of Parkinson's article, that false stories can have a larger effect than the one their creator intended, so we need to be careful what lies we spread. He also points out that fake news throughout our history has always been about building prejudices and creating false reasons for fear and anger.

This article was written by Robert Parkinson, a historian of the American revolutionary era. Basically, it highlights the systematic attempts on the part of John Adams, Benjamin Franklin, and many printers to influence American public opinion through spreading false information. This story was published in the context of the spread of "fake news" during the 2016 election, especially via Facebook. But Parkinson's point, which is essentially the argument of his recent book The Common Cause: Creating Race and Nation in the American Revolution, has to do with the content of the "fake news" Franklin and his colleagues spread through American newspapers. They sought to mobilize support for the revolution by highlighting supposed massacres by Native Americans. These alleged massacres, it was reported, were encouraged and abetted by the British. By mobilizing anti-Indian sentiment, the revolutionaries created a group of people who were defined as enemies of the new United States. This encouraged violence against Native peoples. (He makes the same point about enslaved people and African Americans in general in his book.) He points out that today's fake news is, like that in the past, "about stirring up fear and passions" and about "who belongs to the republic and who does not." More broadly, he shows that throughout history, demonizing entire groups of people in the media has had terrible consequences.