If Ron Avery has his way, Philadelphia tour guides will stop telling you things that will make you flunk your history test.

They'll stop saying that George Washington and Abraham Lincoln once dined together. Or that Ben Franklin had not one, but 69, illegitimate children. That basement kitchens had outdoor exits so as to spare the furniture should the cook's skirts catch fire. Or that a house would be left to burn if it didn't display an insurance company fire mark.

Mr. Avery, a part-time tour guide and retired reporter for the Philadelphia Daily News, is out to halt what he sees as "nonsense" parading as history among those paid handsomely to tutor tourists. He compiled a list of 80 inaccuracies he has heard – or heard of – while traveling incognito over the years on tourist trolleys, double-decker buses, and horse-drawn carriages in this most historic of American cities, where both the Declaration of Independence and the US Constitution were drafted in the late 1700s. Avery sent his list to the city council, where he found a friend in Councilwoman-at-large Blondell Reynolds Brown.

Like Avery, who started his career as a high school history teacher, Ms. Brown is a former teacher and abhors misinformation. "I think we have the responsibility to offer up the best face of our city. If there are inaccuracies, we have the responsibility to do something about it," she says.

So Brown introduced a bill last spring to educate, test, and license guides who offer tours for money on public property in Philadelphia, which brought forth not just the nation's political system, but many of its most important cultural, scientific, and social institutions. Comment on the measure resumes next month in anticipation of a vote later this year. A $150 fee has been suggested, as have training classes and manuals, annual testing, and a $300 fine for giving a tour without a license. No penalty has yet been set for those who place Lincoln and Washington at the dinner table together.

If enacted, the law would almost certainly make tour guide certification mandatory. Though other cities – including New York and Washington – have ordinances governing tour guides, the Philadelphia bill is by no means assured of passing. Avery simply wants all guides to know a handful of accurate details about each historic site. Of the potter's field that became today's idyllic Washington Square, for instance, they might be required to know that it contains the remains of 2,000 Revolutionary War dead, as well as the tomb of that war's unknown soldier. The fact that George Washington himself – breathing through a straw – sat for the cast of his statue that's in this park, or that there's a very small chance the remains in the tomb may actually be those of a British soldier, would be optional and not tested.