Kind of fun. You click on the American city you think has the highest population until you get to just one city and it gives you a score. I got 51 out of 63. Many were pure guesses.
https://www.census.gov/dataviz/visualizations/057/
I'm curious to see what score someone who doesn't live in the US would get. I would imagine that for a foreigner, 50% of the cities are ones you would never have heard of
My score was 43, better than random at least!
Got 53 for the cities and 59 for the states.