What's your accent?

[Kuumo]

Most similar: New York, Jersey City, Yonkers
Least similar: Des Moines, Akron, Omaha

There is very little red on the map, which is extremely unsurprising since I am not a native speaker, I have never lived in an English-speaking country, and I usually try to follow British English.

I like how the redder areas tend to have more Italian Americans.

[Kuumo]

Most similar: New York, Jersey City, Yonkers
Least similar: Des Moines, Akron, Omaha

There is very little red on the map, which is extremely unsurprising since I am not a native speaker, I have never lived in an English-speaking country, and I usually try to follow British English.

I like how the redder areas tend to have more Italian Americans.

I... don't think there's a particular correlation? Hawaii and San Jose are not exactly famous for Italian Americans, while places such as Buffalo, Cleveland and Chicago are in blue.
On the other hand, the Ohio/Mississippi rivers form a very visible demarcation, and I am not sure why.

It's almost certainly just a funny coincidence since most Italian Americans today don't speak any Italian. You can see that Minnesota and the Dakotas aren't super dark red on Astatine's map even though they have the most German Americans.

[Kuumo]

The most similar cities were San Antonio, Irving, and Fort Worth because I lived in Texas in my younger years. The least similar cities were Philadelphia, Worcester, and Providence. I can attest that people with a strong Boston accent are the hardest Americans for me to understand, and this map illustrates that.