Love your quiz but could have done with more time as Im not american. Kiwi from New Zealand, only managed to get 20 but I could have gotten more if i had more time
Charleston, SC, and Nashville, TN are now the largest cities in their states. Also, "New York" should be accepted, especially since the word "City" is not officially even part of the name.
I see the quiz was last updated in 2014 so no shade, but agree with earlier comments that this quiz should be updated. In addition to earlier suggestions, Huntsville, AL is now the largest city in Alabama.