1. Plano, Texas

Plano started off as a small and quiet farming community, and it may seem like an unlikely place to be the happiest in America. However, it is now home to over 280,000 residents, several Fortune 1000 companies, and more than 10,000 businesses total.

Plano is the ninth-largest city in Texas and the fourth-largest in the Dallas Fort Worth region. Yet, in the 2000s, it had both the highest median income and the lowest crime rate among US cities with populations surpassing 250,000.