Over the past 150 years, the boundaries and demographics of South Nashville have changed dramatically. Starting out as an industrial and blue-collar area comprised of factories, mills, and rail yards, the area quickly grew, drawing thousands looking for employment or more affordable housing. South Nashville has traditionally been the most diverse part of the city, racially and culturally. During the past 30 years, stark changes have transformed the appearance of the southern portion of Nashville and Davidson County. Urban renewal programs and the construction of interstate highways resulted in the removal of thousands of buildings deemed as substandard, further obliterating traditional neighborhoods. Today, the district faces new challenges as many established neighborhoods now cope with gentrification.