Crossing the Threshold: Overpopulation in the United States


You are one of many on the planet. You leave your own ecological and environmental footprint on the world and your country. There needs to be land to grow your food, gas to drive your car, and space to put your landfill. And as small as everyone’s effects are on the world around them, when a place has such a large number of people, those effects become devastatingly unsustainable. Has the United States reached this threshold, when its population is too large to support? And if so, is there anything we can do to save the country and the environment?

Here’s a short overview of my topic.

What Is Overpopulation and Why Does it Matter?

A place is generally considered overpopulated when it cannot indefinitely and sustainably support its population. An overpopulated area does not provide enough resources and open space for future generations, and it may already have to deal with issues of pollution and unhealthy conditions (FAIR “The United States is Already Overpopulated”). A growing or too large population seems to be the base of so many problems facing America today: global warming, encroachment on the wilderness, and housing crises, to name a few. And in addition to current problems, it is irresponsible to not leave ample resources, a healthy environment, and open spaces for generations to come.

Is the United States Overpopulated?

The United States of America is the world’s third largest country, at a population of around 328 million people (WPB). It is the only large developed country that is expected to continue growing exponentially, with a projected population of 439 million people  by 2050 (WPB; FAIR “The United States is Already Overpopulated” ). Already, we are using our renewable resources at twice the speed they can be renewed (WPB). Water table reserves are becoming more and more depleted. Water shortages are beginning to become a problem all over the country (WPB). And unsustainable farming practices as well as centuries of farming have led to over 100 million acres of American farmland being rendered useless due to erosion and loss of soil (D’Antonio). Nearly half of all lakes, rivers, and estuaries are too polluted to be considered safe (FAIR “The United States is Already Overpopulated” ). Examples of this pollution can be seen in the Bay Area, where Lake Merritt and many parts of the bay are too filled with trash and chemicals to support much life. I would argue that, yes, the United States is overpopulated, and many of its effects can already be felt. The country is not sustainably supporting its population without hurting the environment and is growing too fast to save open space, bodies of water, and resources for future generations.

Why Am I Interested in This Topic?

I was first drawn to the topic of overpopulation because it is a large, arguably the largest, issue that America is facing today, but it is rarely talked about or addressed. Population growth and size is the root of so many issues: from deforestation to city crowding. I began to wonder if America’s population growth could be addressed, how many other issues could be solved or mitigated? You can read a full essay on my personal interest and an overview of the topic here:

When Did Overpopulation Begin?

Population growth is not a recent phenomenon in North America. The land of the United States has been populated by  small, sustainable numbers of Native Americans for 40-50,000 years (US History 10 Class Notes). In the early 1600s, the first immigrants began to move from Europe to colonies in America (US History 10 Class Notes). While they began to immigrate in large numbers, increasing the number of people entering the colonies, they also brought disease that decimated 90% of the Native American population during the following 150 years (Kennedy). The early years of the United States saw great population growth, with the population increasing by around 33% every decade between 1790 and 1850 (Census Bureau). This growth was not a problem because at the same time, the United States’ land area was expanding as well. The Louisiana Purchase in 1803 and successive annexations throughout the next 50 years provided ample space and resources for America’s population (US History 10 Notes).

Overpopulation was first noticed in the 1970s, after a huge population surge due to the baby boom and increased immigration. A strong economy after World War II led to a huge surge in birthrate, as families felt like they had enough money to support more children (Haines). The Immigration and Nationality Act of 1965, which allowed for a significant increase in immigration, also contributed to the population growth in the 1970s (FAIR “History of US Immigration Laws”).

While birth rates in the United States have generally been decreasing in the past century, the post WWII period (1945-1960) saw a huge increase in average family size.
The number of immigrants in the United States was steadily increasing until the Immigration Act of 1924 severely restricted entrance. However, following the more lenient 1965 Immigration and Nationality Act, immigration skyrocketed (FAIR “History of US Immigration Laws”).

In the 1970 census, there was an average of 57.5 people per square mile, more than five times the density 100 years earlier (Census Bureau). Even at this time, oil reserves and water tables were being diminished at alarming rates. America was not able to keep up with the demands of its population with its own resources, leading to a large amount of importation from other countries at great economic and environmental costs. Land and air pollution were starting to become noticeable in many areas (Ehrlich). Many experts began to blame the United States’ growing population as the reason for these new problems (Ehrlich). You can read my full essay on the history of overpopulation in the United States here:

What Causes Population Growth?

The two main factors affecting population size and growth are birth rate and immigration. 55% of population growth in the last 50 years was due to first and second generation immigrants, and 88% of growth in the next 50 years is expected to come from immigration as well (Passel). If immigration continues at its current level, the population is expected to be 399 million by 2050 (Ortman).

Birth rate, or the number of children born in the United States, also contributes significantly to population growth. The birth rate in America has dropped sharply in the last 10 years, but it is still significantly above many European nations. Currently, the birth rate is just below the “replacement level”, 2.1 births per woman, or the level needed to sustain a steady population (Mather). However, due to immigration, the United States is still seeing steady population growth (Passel).

What Is the Current Situation?

Since 1970, the situation has only gotten worse. The population density in 2017 was around 92 people per square mile, up from only 58 in 1970 (“Population Density”; Census Bureau). The population is now 328 million people, over 120 million more people than 50 years ago (WPB; Census Bureau).

And the effects of a large population are currently being felt. Between 1990 and 2003, the United States’ per capita (per person) CO2 emissions rose only 3.2%; however, the country’s overall emissions rose by 20.2% (Staples). Greenhouse gas emissions in the United States are clearly not all related to increased per capita consumption, but by a general population increase. The public school system is also being strained by overpopulation. New schools are constantly being built and new teachers are being hired at high costs. Shortages of qualified educators have led to many unqualified teachers being hired. The high cost of new school buildings is causing overcrowded classrooms and therefore decreased quality of education (“What Do We Know”). Overpopulation even affects American democracy. In 1790, a member of congress represented 34,000 people. Now, a member represents 735,000 people (WPB). Already, overpopulation is beginning to take a toll on quality of life and the environment. And with a population still growing, the effects are only going to get worse (WPB). You can read my full essay about the current situation of overpopulation here:

What Can We Do?

Luckily, overpopulation has been receiving more attention from the media recently. Many different groups have produced many different solutions. Some proposals are good, but others are problematic.

Two large lobbying groups, the Federation for American Immigration Reform (website: ) and the Center for Immigration Studies (website: ), advocate for a severe restriction or even a stop to immigration. They support a zero net immigration policy, which would only allow as many immigrants as emigrants leaving the United States. According to predictions from the Census Department, a zero net immigration policy would cause the population to shrink as early as 2050 (Ortman). However, I would argue that considerably restricting immigration should not be done, because it goes against the American concept of being a nation of immigrants. The United States has always prided itself on being a safe haven for people seeking asylum or a better life, so it would be unfair to suddenly shut them out. In addition, both the Federation for American Immigration Reform and the Center for Immigration Studies have been deemed hate groups by the Southern Poverty Law Center for supporting racist immigration legislation. You can learn more about those controversies here: and

A new immigration policy, lobbied for by experts such as Henry W. Kendall, is to lower immigration not through restriction but through getting to the root of the problem: violence and poverty in other countries. Kendall argues that the most ethical and effective solution to overpopulation is increasing the global quality of life, lowering worldwide fertility rates, and decreasing the need for people to come to the United States (D’Antonio). While this solution is expensive and slow, it would solve the root of the problem; instead of refusing people entry into the United States, it would get rid of the need to immigrate.

To solve or at least mitigate the problems related to overpopulation in the United States, there needs to be a mixture of reduced consumption on a personal level, decreased immigration to the United States through aid to struggling countries, and large scale environmental reform.

Family size is a personal choice, and it is unethical to force parents to have fewer children. However, it is important for parents to be educated about population in the United States and the impact of every new person, to make a more informed decision about family size.

What Can You Do?

Making environmental decisions is another way any person can help mitigate the effects of overpopulation. Reducing one’s footprint can be done by making sustainable choices, such as buying energy efficient appliances, driving electric vehicles or taking public transportation, and taking extra effort to recycle and compost. Being environmentally conscious is certainly an effective way of mitigating overpopulation effects, but it is only a short term solution. If nothing is done to curb actual population growth, there will soon be a point when no matter how small people’s consumption levels are, there will still be too many people for the country to handle. You can read my full essay on solutions to overpopulation here:


Thank you so much for reading my page! Please leave a comment below if you have any questions or points to add:

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  1. April 29, 2019 by Karen.Bradley

    Interesting Catalyst page, Ella! You cover a lot of bases, and in a balanced way. I particularly appreciated your getting at the “root of the the problem” by promoting development and education in poorer countries (which strongly correlates with reducing birthrates). Let’s do that, privately and through government efforts. Will you get involved in this?

  2. April 30, 2019 by Catherine.Rosenbaum

    Ella, I love your topic! This is an interesting topic I haven’t seen many people approach, and I thought your debate about immigration in your macro solution was interesting. Do you think that Trump’s interest with the border wall has anything to do with over-population? I thought it was interesting that you brought up how many of the methods used to stop overpopulation are unethical – do you think there are quick ethical ways to reduce population? Again, great project

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