Type 'easy' or 'hard' to begin the quiz. Easy is a 5-degree grid, hard is a 2.5-degree grid. Then, try to name the LARGEST city in each grid square which fits the category label for each square. To name a city, you must first click on the grid square to make it have a GREEN border. Then, type in the city answer for that square followed by a '.' (a period). You are given a score from 0 to 100 based on your answer's population compared to the largest city accepted in that square (100 being you named the largest city).
LETTER: means the city starts with that letter.
NUMBER RANGE: (such as 2-5, 10+) means the city contains that many letters (excluding spaces and special characters).
POPULATION RANGE: (such as 50-100K) means the city has that range for its population.
2+ WORDS means the city name has 2 or more words (words denoted by a space or hyphen).
AK and HI are NOT included in this quiz as they often have grid squares with only one answer for this quiz.
At the end of the quiz the largest population missed answer will show in each unanswered square, and for those answered the largest city will be listed if you didn't answer it.
Quiz Takers 
Based on how your quizzes define “cities,” shouldn’t this list also include towns in New England at state tri-points (and one in far northern New Hampshire that spans between Vermont and Maine)?
I think you might also be missing two at the tri-point of New Jersey, Delaware, and Pennsylvania, and two or three (hard to tell from Google Maps) at the tri-point of Kentucky, West Virginia, and Ohio. Some of these places are pretty obscure, but it seems they should count all the same.
I also don’t see the city limits of Joplin touching either state boundary in any maps I’ve looked at.
Which places, you can name them here. Joplin does in fact have a tiny part that reaches the KS-OK tripoint, if you Google Joplin city limits you’ll see a couple maps.
what about cairo, il?
Doesn’t border, bridges don’t count.
?? This doesn’t have anything to do with bridges. The city limits of Cairo include portions of the border between IL-KY and IL-MO. Those borders are in the Ohio and Mississippi rivers, resp. But it’s no different from Weirton, which is across the Ohio river from OH, or East Liverpool which is across the Ohio river from WV.
Or Sioux City which is bordered by the Missouri (NE) and Big Sioux River (SD). Or Washington, DC. which is across the Potomoc from VA.
Ah I see, for some reason wasn’t in the census listing of such cities – will add.
Philadelphia doesn’t count?
nope city limits do not go down to DE