Wakko's question reads "capitols" instead of "capitals"
Wakko states that the name of Missouri's capital is Jefferson, Missouri. The actual name is Jefferson City, Missouri.
To preserve the song's meter, Wakko accents some of the city and state names on the wrong syllable. Most notable is the South Dakotan capital Pierre, which Wakko speaks in the French way, rhyming with "chair," even though South Dakotans rhyme it with "cheer."
Wakko's mission is to name "all 50 states and their capitals," and he succeeds with only a few accent/syllable gaffes. However, as a bonus, he includes a 51st entity in the list - Washington, D.C., which wasn't a state until 2020.