According to the Gale Guide to Cities of the United States:
"Hartford, Connecticut's state capital and second largest city, is known as "the insurance capital of the world."
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The world's chocolate capital is Belgium
Rayne, Louisiana, is known as the frog capital of the world.
Greenville is known as the towboat capital of the world.
The city of Hartford is the capital of the state of Connecticut and is considered to be the Insurance capital of the World.
Rome, Italy is known as the eternal city.
Lisbon
Nuremberg.
Caracas, Venezuela
Wausau, Wisconsin
Detroit, Michigan.
Detroit
No city in California is known as the "Onion Capital of the World." That title belongs to the city of Elba, located in New York state.