Historically, the United States population was heavily concentrated in the Northeast and Midwest, driven by early colonization, rapid industrialization, and major ports of entry for European immigrants during the 19th and early 20th centuries. However, beginning in the mid-20th century, the advent of widespread residential air conditioning, shifting economic opportunities, and a desire for milder climates spurred a massive demographic shift toward the "Sun Belt." Consequently, for the past several decades, the South and West regions have experienced the most rapid and sustained population growth, fundamentally rebalancing the nation's political and economic center of gravity away from the historically dominant Rust Belt and Northeast.

Explore historical population data by region:

• 1910
• 1920
• 1930
• 1940
• 1950
• 1960
• 1970
• 1980
• 1990
• 2000
• 2010
• 2020