When and why did the sunbelt states begin to develop?

The Sunbelt states began to develop significantly in the mid-20th century, particularly during the post-World War II era. This growth was driven by a combination of factors, including a warmer climate, a burgeoning aerospace and technology industry, and the expansion of the defense sector. Additionally, the migration of populations from the Northeast and Midwest to the South and Southwest was fueled by the search for jobs, lower living costs, and lifestyle changes. This transformation was further accelerated by the rise of air conditioning and improvements in infrastructure, making these regions more appealing for both businesses and families.