WASHINGTON — Since Harry Truman, every president who has left office on his own terms — and even Richard Nixon, who didn’t — has given some form of broadcast farewell address to the nation.

But the tradition goes all the way back to George Washington, whose 1796 farewell address still echoes through the words of departing presidents even two centuries later.

With a few exceptions, the addresses follow a distinctly American formula: An expression of optimism for the future, some advice for future generations, and a professed heartfelt desire to return to civilian life.

George Washington

Washington’s farewell address wasn’t delivered as a speech. Instead, it was published in a Philadelphia newspaper in September, 1796. And it wasn’t his last address: He delivered his final State of the Union address three months later.

It’s still considered the one of the greatest addresses in American history, and is remembered for the advice that Washington gave to the young country — advice succeeding generations have consistently ignored.

Washington warned against entangling alliances with Old World powers: “It is our true policy to steer clear of permanent alliances with any portion of the foreign world, so far, I mean, as we are now at liberty to do it; for let me not be understood as capable of patronizing infidelity to existing engagements,” he wrote. “I repeat, therefore, let those engagements be unwise to extend them.”

He warned against partisanship: “The alternate domination of one faction over another, sharpened by the spirit of revenge natural to party dissension, which in different ages and countries has perpetrated the most horrid enormities, is itself a frightful despotism.”

And he when warned against regional rivalries between North and South, Atlantic and West, he may well have been writing about red states and blue states.

“One of the…