Presidents receive a salary because the Constitution requires it, stipulating that the amount cannot be changed while a person is in office. U.S. law puts the president's annual paycheck at $400,000, plus $50,000 in expenses.

As a result, Washington did take a salary of $25,000, a sizable sum for the times. And as of Monday, we know that Trump's “intention right now,” according to what press secretary Sean Spicer said in a briefing, is to donate his salary at the end of the year. “He made a pledge to the American people, he wants to donate it to charity and he'd love your help to determine where it should go,” Spicer said to reporters.

The irony, of course — at a time when questions continue to be asked about overlapping interests between Trump's presidency and his businesses — is that one of the very reasons the framers wanted the president to take a salary, even if they were wealthy enough not to need it, was to avoid potential conflicts of interest. It was also designed to send the signal that anyone — not just the wealthy elite — could become president, and served as a reminder that the president is a public servant to the citizens who pay him a salary.

Rice University historian Douglas Brinkley said in an interview that in the case of Washington, a wealthy landowner, taking a salary meant that if a bad fate befell his properties, having a salary could keep him from succumbing to the temptation of potential corruption. “You come in, you have all these rich holdings, but if for some unforeseen reason a storm wipes out all your crops and now you're broke and in debt, you would at least have money to live on,” and not become “beholden to moneyed interests.”