The map of the United States above depicts the evolution of the nation’s population density in over 200 years, from 1790 to 2010.
The United States has undergone a remarkable transformation in population density since its founding. From the initial clusters of settlements along the Eastern Seaboard to the coast-to-coast development we see today, the story of America’s population growth reflects its political, economic, and cultural evolution.
Colonial Origins (1790)
In 1790, when the first U.S. census was conducted, approximately 3.9 million people inhabited the young nation, with population centers concentrated primarily in the original 13 colonies.
The average density was merely 4.5 people per square mile across settled areas.
Early Westward Movement (1800-1840)
By 1800, population patterns began shifting westward, crossing the Appalachian Mountains into what would become Kentucky, Tennessee, and Ohio.
The Louisiana Purchase of 1803 doubled the nation’s territory, opening vast new lands for settlement.
The Great Migration To The West (1840-1890)
The 19th century saw dramatic acceleration in westward migration.
The completion of the Erie Canal in 1825 facilitated movement to the Great Lakes region, while the California Gold Rush of 1849 pulled thousands to the Pacific Coast. The Homestead Act of 1862 offered 160 acres of public land to settlers willing to develop it, further encouraging westward expansion.
By 1850, the U.S. population had grown to 23 million people. The construction of the transcontinental railroad, completed in 1869, revolutionized cross-country travel and accelerated settlement of the Great Plains and Mountain West.
Industrialization & Immigration (1890-1950)
The turn of the 20th century marked significant changes in America’s demographic landscape.
Immigration surged, with more than 12 million newcomers arriving through Ellis Island between 1892 and 1954. Urban centers swelled during the Industrial Revolution as people moved from farms to factories.
By 1950, with 151 million residents, the population distribution reflected modern patterns, with major metropolitan areas across all regions of the country. The post-World War II economic boom fueled suburbanization and the development of the Sunbelt states.
Modern Population Patterns (1950-2010)
The 2010 census recorded 308.7 million Americans, with population density reaching 87.4 people per square mile nationwide.
Density varied dramatically by region: parts of the Northeast corridor exceeded 1,000 people per square mile, while large areas of Alaska, Nevada, and Wyoming maintained fewer than 2 people per square mile.
Geography & Continuing Evolution
As of 2024, the population of the United States stands at over 340 million people, according to the U.S. Census Bureau. The most densely-populated state is New Jersey, with just over 1,200 people per square mile.
Today’s map of U.S. population density reflects not just 220+ years of migration and natural growth, but also the underlying geography that shaped settlement patterns. Rivers, harbors, and fertile plains attracted development, while mountain ranges and arid regions remained more sparsely populated.
This demographic evolution continues today, with ongoing shifts from the Rust Belt to the Sunbelt, rural to urban migration, and coastal population concentration – all writing new chapters in America’s population story.
Data sources: U.S. Census Bureau; historical population records (1790-2010)
Found this map interesting? Share it along: