The wild population split of the United States

About 80% of the country's population lives east of this line

You can see where the split happens… Photo by NASA on Unsplash

Population is my jam. If you know anything about me it’s that I’m endlessly fascinated by where people live and, more importantly, where people largely don’t. Often times, within any given country, state, province, etc. there are places where it feels like there should be more people. Like maybe the climate is nice, there’s plenty of arable land to grow food, and maybe it’s near a large river or a coast line and yet… No major city. No large population. No port or even large agriculture output.

What I like most about these kinds of puzzles is that no place ever has the exact same answer. There’s always a bit of nuance in the history and geography that determines the success of any given location. This week, for YouTube, I’ve decided to turn my attention to the Pacific coastline of Oregon and Washington in the United States. And you can watch that right here:

But for this article, I want to go up a scale, all the way to the contiguous United States. Because, if you didn’t know, the US has a pretty extreme population split between its eastern and western halves. So what’s going on?

While the contiguous United States is very large overall, a heavy majority of Americans (approximately 80%) reside east of the 98th meridian west longitude. This invisible line, running roughly through the middle of the Dakotas, Nebraska, Kansas, Oklahoma, and Texas, serves as a demographic dividing line, creating a stark contrast between the densely populated east and the more sparsely settled west.

Now, of course, one of the most logical answers to this is simply that the eastern shore of the United States was settled and colonized by Europeans first. In fact, early American cities like Boston, New York, Philadelphia, and Charleston quickly became centers of commerce and culture during these early days, which laid the groundwork for future population growth in the east.

This isn’t to say the rest of the continent and future country of the United States was empty though. Quite the contrary! Native Americans from hundreds (thousands?) of tribes extended all the way to the Pacific Ocean. And while estimates can vary wildly, the pre-Columbian population of what would become the United States tends to be around 3 million to 12 million people. Given that the population of the entire world during this period was around 500 million people, it’s safe to say that the Americas, in general, were significantly less densely populated than Europe at the time.

Photo by Ric Matkowski on Unsplash

But as the country expanded westward, and Europeans ventured farther and farther inland in search of a place to establish a homestead, the journey became signicantly rougher. The Appalachian Mountains, while an early challenge for homesteaders, were eventually overcome, leading to settlement in the Ohio River Valley and the Great Lakes region. The abundant freshwater, navigable rivers, and rich soils supported agriculture and emerging industries in the states that would become Tennessee, Kentucky, Indiana, Missouri and many more. Basically, once you were over the Appalachian Mountains, the land stretched on endlessly providing a very desireable area where making new cities and towns was realtively easy.

Much of this was because of the climate. You see, basically everywhere east of the 98th meridian is generally more humid and receives more consistent rainfall, making it highly suitable for diverse agricultural practices. This favorable climate contrasts sharply with the often arid or semi-arid conditions found further west, particularly once beyond the 100th meridian, a line often cited as the beginning of the Great American Desert.

Now, given all this connectedness, industrialization took root predominantly in the east, fueled by access to raw materials (coal and iron), a growing labor force (mostly from Europe), and established trade routes that were made easy by the mostly easy terrain. Factories clustered around cities, attracting even more people seeking employment and opportunity. Even as the country embraced its new agricultural heartland in the Midwest and prairies, the core of industrial and financial power remained, and largely still remains, in the east.

Photo by Joshua Woroniecki on Unsplash

But the west is different than the east! While breathtaking in its natural beauty, vast mountain ranges, deserts, and a more far more variable climate made (and continues to make) large-scale agriculture more difficult without significant irrigation and infrastructure. Resource extraction, such as mining for gold, silver, and other minerals, drew populations to specific areas (hello Comstock Lode), but these booms were often localized and did not always lead to sustained, widespread settlement in the same manner as the agricultural and industrial growth in the East. Even today, the western states, with exceptions like the Pacific Coast (and even then mostly localized to the Los Angeles and San Francisco regions), often feature widely spaced urban centers amidst vast stretches of open land. There’s also just far fewer large expanses of land in the east. Certainly nothing like the midwest region of the United States.

All in all, it’s not that surprising that the eastern half of the contiguous United States is still home to about 80% of the total population when you look at all the variables. In fact, I’d argue it’s more impressive that the west has even 20%! And were it not for the explosive growth of California during the mid-1900s, largely due to mineral wealth and the incredibly fertile Central Valley, the west would likely have less than 10% of the population. Which is just kind of fun to think about in a ‘what if’ sort of way.