At the moment, there are around 326 million people living in the United States, a country that’s 3.5 million square miles (9.8 million sq km) in land area.
But, as Visual Capitalist's Jeff Desjardins explains below, throughout the nation’s history, neither of these numbers have stayed constant.
Not only did the population boom as a result of births and immigrants, but the borders of the country kept changing as well – especially in the country’s early years as settlers moved westwards.
U.S. Population Density Over Time
Today’s animated map, which comes to us from Vivid Maps, plots U.S. population density numbers over the time period of 1790-2010 based on U.S. Census data and Jonathan Schroeder’s county-level decadal estimates for population. In essence, it gives a more precise view of who moved where and when over the course of the nation’s history.
Note: While U.S. Census data is granular and dates back to 1790, it comes with certain limitations. One obvious drawback, for example, is that such data is not able to properly account for Native American populations.
“Go West, Young Man”
As you might notice in the animation, there is one anomaly that appears in the late-1800s: the area around modern-day Oklahoma is colored in, but the state itself is an “empty gap” on the map.
The reason for this? The area was originally designated as Indian Territory – land reserved for the forced re-settlement of Native Americans. However, in 1889, the land was opened up to a massive land rush, and approximately 50,000 pioneers lined up to grab a piece of the two million acres (8,000 km²) opened for settlement.
While settlers flocking to Oklahoma is one specific event that ties into this animation, really the map shows the history of a much broader land rush in general: Manifest Destiny.
You can see pioneers landing in Louisiana in the early 1800s, the first settlements in California and Oregon, and the gradual filling up of the states in the middle of the country.
By the mid-20th century, the distribution of the population starts to resemble that of modern America.
Population Density Today
The average population density in the U.S. is now 92 people per square mile, although this changes dramatically based on where you are located:
If you are in Alaska, the state with the lowest population density, there is just one person per square mile – but if you’re in New York City there are 27,000 people per square mile, the highest of any major city in the country.