The leading causes of death in the United States have changed significantly from the year 1900 to the present. Leading causes of death in 1900, such as tuberculosis, gastrointestinal infections, and diphtheria have seen huge decreases in death rates and are no longer among the leading causes of death in the United States. However, other diseases such as heart disease and cancer have seen increased death rates. Vaccinations One major factor contributing to the decrease in death rates for many diseases since the year 1900 is the introduction of vaccinations. The decrease seen in the rates of death due to pneumonia and influenza is a prime example of this. In 1900, pneumonia and influenza were the leading causes of death, with around 202 deaths per 100,000 population. However, in 2023 pneumonia and influenza were not even among the ten leading causes of death. Cancer One disease that has seen a large increase in death rates since 1900 is cancer. Cancer currently accounts for almost 20 percent of all deaths in the United States, with death rates among men higher than those for women. The deadliest form of cancer for both men and women is cancer of the lung and bronchus. Some of the most common avoidable risk factors for cancer include smoking, drinking alcohol, sun exposure, and obesity.

Rank, number of deaths, percentage of deaths, and age-specific mortality rates for the leading causes of death, by age group and sex, 2000 to most recent year.

In the United States in 2021, the death rate was highest among those aged 85 and over, with about 17,190.5 men and 14,914.5 women per 100,000 of the population passing away. For all ages, the death rate was at 1,118.2 per 100,000 of the population for males, and 970.8 per 100,000 of the population for women. The death rate Death rates generally are counted as the number of deaths per 1,000 or 100,000 of the population and include both deaths of natural and unnatural causes. The death rate in the United States had pretty much held steady since 1990 until it started to increase over the last decade, with the highest death rates recorded in recent years. While the birth rate in the United States has been decreasing, it is still currently higher than the death rate. Causes of death There are a myriad number of causes of death in the United States, but the most recent data shows the top three leading causes of death to be heart disease, cancers, and accidents. Heart disease was also the leading cause of death worldwide.

Since the 1780s, over 25,000 United States law enforcement officers have died while on active duty, or due to injuries and illnesses obtained while on duty. Gunfire is responsible for over half of all total law enforcement deaths recorded, particularly before the 1930s. From this point on, the total share of gunfire deaths has decreased significantly, mostly due to the increase in vehicle or health related deaths, although gunfire has remained the most common individual cause of death in almost every year. Gunfire deaths These deaths rose steadily after the Civil War, and peaked at over 200 annual deaths during the 1920s, due to the increase in criminal activity during prohibition. Because of this, the National Firearms Act of 1934 was introduced in an attempt to reduce gun-related crime, by requiring the registration of any transfer of ownership and imposing a tax on gun manufacturers and distributors. After Prohibition's end and the introduction of these measures, annual law enforcement deaths from gunfire have been well below 100 in almost every year, except for a brief spike in the early 1970s, during the crime wave that began in the 1960s and the beginning of the "War on Drugs". Overall, gunfire deaths of law enforcement have fallen since the 1970s, reaching a low of just 34 deaths in 2013. In contrast, the total number of people killed by police shootings has consistently been above one thousand for most of the past decade.

Increase in health-related deaths

The majority of non-gunfire deaths are a result of vehicle-related accidents, and the number of crashes and accidents rose throughout the 20th century in line with the increase in car ownership. However, the number of deaths from heart attacks and job-related illness has also risen over time, due to the aging of the population and increasingly unhealthy lifestyle trends across the country. In recent decades, additional health issues have emerged that have had a disproportionate impact on law enforcement. In 2001, 72 officers died as a result of the September 11th terrorist attacks, and over 350 additional deaths have been attributed to the adverse health effects (primarily respiratory illnesses) sustained by first responders from law enforcement. From 2020-2022, COVID-19 became the largest single cause of law enforcement deaths. Figures relate to cases where the individual contracted COVID-19 while on duty, and highlights the increased exposure to the virus faced by those considered to be frontline or essential workers. This number is likely to fall in the future as infection rates fall and newer strains of the virus are less lethal.

Motor-vehicle deaths in the United States have decreased greatly since the 1970s and 1980s. In 2023, there were around 13.4 deaths from motor vehicles per 100,000 population, compared to a rate of 26.8 deaths per 100,000 in 1970. Laws requiring drivers and passengers to wear safety belts and advancements in safety technology in vehicles are major drivers for these reductions. Motor-vehicle accidents in the U.S. Americans spend a significant amount of time behind the wheel. Many cities lack convenient and reliable public transportation and, especially in rural areas, cars are a necessary means of transportation. In 2020, August was the month with the highest number of fatal crashes, followed by September and June. The deadliest time of day for fatal vehicle crashes is between 6 and 9 p.m., most likely due to the after-work rush hour and more people who are under the influence of alcohol. Drinking and driving among youth Drinking and driving remains a relevant problem across the United States and can be especially problematic among younger inexperienced drivers. As of 2017, around 5.5 percent of high school students reported they had driven while under the influence of alcohol. Drinking and driving is more common among males than females, and Hispanic males reported drinking and driving more than other races or ethnicities.

The child mortality rate in the United States, for children under the age of five, was 462.9 deaths per thousand births in 1800. This means that for every thousand babies born in 1800, over 46 percent did not make it to their fifth birthday. Over the course of the next 220 years, this number has dropped drastically, and the rate has dropped to its lowest point ever in 2020 where it is just seven deaths per thousand births. Although the child mortality rate has decreased greatly over this 220 year period, there were two occasions where it increased; in the 1870s, as a result of the fourth cholera pandemic, smallpox outbreaks, and yellow fever, and in the late 1910s, due to the Spanish Flu pandemic.

Firearms and explosives (although mostly firearms) have been the most common method of death by suicide since the early 1900s. Poisoning was generally the second-most common method, although there were some years where there were more suicide deaths due to hanging or strangulation. In this period, the suicide rate peaked in the early-1930s, at the height of the Great Depression, with almost 20,000 deaths by suicide in 1932 alone. Although the total number of deaths by suicide in the given period was highest in 1970, it is important to note that the U.S. population grew significantly during the 20th century and the suicide rate at this time was much lower than in the 1930s. Additionally, records were generally less reliable in early years, therefore many suicides may have gone unrecorded, may have been miscategorized as homicide or natural death, or miscategorized by method.

The Holocaust was the systematic extermination of Europe's Jewish population in the Second World War, during which time, up to six million Jews were murdered as part of Nazi Germany's "Final Solution to the Jewish Question". In the context of the Second World War, the term "Holocaust" is traditionally used to reference the genocide of Europe's Jews, although this coincided with the Nazi regime's genocide and ethnic cleansing of an additional eleven million people deemed "undesirable" due to their ethnicity, beliefs, disability or sexuality (among others). During the Holocaust, Poland's Jewish population suffered the largest number of fatalities, with approximately three million deaths. Additionally, at least one million Jews were murdered in the Soviet Union, while Hungary, Latvia, Lithuania, the Netherlands and Yugoslavia also lost the majority of their respective pre-war Jewish populations. The Holocaust in Poland In the interwar period, Europe's Jewish population was concentrated in the east, with roughly one third living in Poland; this can be traced back to the Middle Ages, when thousands of Jews flocked to Eastern Europe to escape persecution. At the outbreak of the Second World War, it is estimated that there were 3.4 million Jews living in Poland, which was approximately ten percent of the total population. Following the German invasion of Poland, Nazi authorities then segregated Jews in ghettos across most large towns and cities, and expanded their network of concentration camps throughout the country. In the ghettos, civilians were deprived of food, and hundreds of thousands died due to disease and starvation; while prison labor was implemented under extreme conditions in concentration camps to fuel the German war effort. In Poland, six extermination camps were also operational between December 1941 and January 1945, which saw the mass extermination of approximately 2.7 million people over the next three years (including many non-Poles, imported from other regions of Europe). While concentration camps housed prisoners of all backgrounds, extermination camps were purpose-built for the elimination of the Jewish race, and over 90% of their victims were Jewish. The majority of the victims in these extermination camps were executed by poison gas, although disease, starvation and overworking were also common causes of death. In addition to the camps and ghettos, SS death squads (Einsatzgruppen) and local collaborators also committed widespread atrocities across Eastern Europe. While the majority of these atrocities took place in the Balkan, Baltic and Soviet regions, they were still prevalent in Poland (particularly during the liquidation of the ghettos), and the Einsatzgruppen alone are estimated to have killed up to 1.3 million Jews throughout the Holocaust. By early 1945, Soviet forces had largely expelled the German armies from Poland and liberated the concentration and extermination camps; by this time, Poland had lost roughly ninety percent of its pre-war Jewish population, and suffered approximately three million further civilian and military deaths. By 1991, Poland's Jewish population was estimated to be just 15 thousand people, while there were fewer than two thousand Jews recorded as living in Poland in 2018.

Liver cirrhosis is a chronic disease, which occurs when long-term damage and scarring to the liver prevents it from functioning to its full capacity. Although the human liver is the only organ with the capacity to regenerate itself; there is no cure for liver cirrhosis, however the effects of the condition can be slowed and even minimalized by removing the cause of the damage. The most common causes of liver cirrhosis are alcohol abuse and hepatitis. While hepatitis can be combatted with vaccinations and medication, alcohol abuse can be more complicated due to the psychological impact it has on the user. The prevention of alcohol abuse and its side-effects was one of the major aims of the Prohibition movement in the United States in the 1920s, and records show that the number of deaths due to liver cirrhosis decreased greatly during the Prohibition era, and rose again following Prohibition's repeal in 1933. In the early 1900s, the death rate due to cirrhosis of the liver was as high as 14.8 deaths per 100,000 people, however it gradually fell in the wartime Prohibition of the First World War, and then plateaued at half of this level, between 7.1 and 7.5 deaths per 100,000 people, during federal Prohibition in the 1920s and early 1930s. After Prohibition was repealed at the end of 1933, deaths due to liver cirrhosis increased again, and by the late 1960s, the rate was consistently double it's Prohibition era level.

Over the past 160 years, life expectancy (from birth) in the United States has risen from 39.4 years in 1860, to 78.9 years in 2020. One of the major reasons for the overall increase of life expectancy in the last two centuries is the fact that the infant and child mortality rates have decreased by so much during this time. Medical advancements, fewer wars and improved living standards also mean that people are living longer than they did in previous centuries.

Despite this overall increase, the life expectancy dropped three times since 1860; from 1865 to 1870 during the American Civil War, from 1915 to 1920 during the First World War and following Spanish Flu epidemic, and it has dropped again between 2015 and now. The reason for the most recent drop in life expectancy is not a result of any specific event, but has been attributed to negative societal trends, such as unbalanced diets and sedentary lifestyles, high medical costs, and increasing rates of suicide and drug use.

The child mortality rate in the United Kingdom, for children under the age of five, was 329 deaths per thousand births in 1800. This means that approximately one in every three children born in 1800 did not make it to their fifth birthday. Over the course of the next 220 years, this number has dropped drastically, particularly in the first half of the twentieth century, and the rate has dropped to its lowest point ever in 2020 where it is just four deaths per thousand births.

The child mortality rate in Canada, for children under the age of five, was 333 deaths per thousand births in the year 1830. This means that one third of all children born in 1830 did not make it to their fifth birthday. Child mortality remained above 25 percent for the remainder of the nineteenth century, before falling at a much faster rate throughout the 1900s. By the year 2020, Canada's child mortality rate is expected to be just five deaths per thousand births.

Most estimates place the total number of deaths during the Second World War at around 70-85 million people. Approximately 17 million of these deaths (20-25 percent of the total) were due to crimes against humanity carried out by the Nazi regime in Europe. In comparison to the millions of deaths that took place through conflict, famine, or disease, these 17 million stand out due to the reasoning behind them, along with the systematic nature and scale in which they were carried out. Nazi ideology claimed that the Aryan race (a non-existent ethnic group referring to northern Europeans) was superior to all other ethnicities; this became the justification for German expansion and the extermination of others. During the war, millions of people deemed to be of lesser races were captured and used as slave laborers, with a large share dying of exhaustion, starvation, or individual execution. Murder campaigns were also used for systematic extermination; the most famous of these were the extermination camps, such as at Auschwitz, where roughly 80 percent of the 1.1 million victims were murdered in gas chambers upon arrival at the camp. German death squads in Eastern Europe carried out widespread mass shootings, and up to two million people were killed in this way. In Germany itself, many disabled, homosexual, and "undesirables" were also killed or euthanized as part of a wider eugenics program, which aimed to "purify" German society.

The Holocaust Of all races, the Nazi's viewed Jews as being the most inferior. Conspiracy theories involving Jews go back for centuries in Europe, and they have been repeatedly marginalized throughout history. German fascists used the Jews as scapegoats for the economic struggles during the interwar period. Following Hitler's ascendency to the Chancellorship in 1933, the German authorities began constructing concentration camps for political opponents and so-called undesirables, but the share of Jews being transported to these camps gradually increased in the following years, particularly after Kristallnacht (the Night of Broken Glass) in 1938. In 1939, Germany then invaded Poland, home to Europe's largest Jewish population. German authorities segregated the Jewish population into ghettos, and constructed thousands more concentration and detention camps across Eastern Europe, to which millions of Jews were transported from other territories. By the end of the war, over two thirds of Europe's Jewish population had been killed, and this share is higher still when one excludes the neutral or non-annexed territories.

Lebensraum Another key aspect of Nazi ideology was that of the Lebensraum (living space). Both the populations of the Soviet Union and United States were heavily concentrated in one side of the country, with vast territories extending to the east and west, respectively. Germany was much smaller and more densely populated, therefore Hitler aspired to extend Germany's territory to the east and create new "living space" for Germany's population and industry to grow. While Hitler may have envied the U.S. in this regard, the USSR was seen as undeserving; Slavs were the largest major group in the east and the Nazis viewed them as inferior, which was again used to justify the annexation of their land and subjugation of their people. As the Germans took Slavic lands in Poland, the USSR, and Yugoslavia, ethnic cleansings (often with the help of local conspirators) became commonplace in the annexed territories. It is also believed that the majority of Soviet prisoners of war (PoWs) died through starvation and disease, and they were not given the same treatment as PoWs on the western front. The Soviet Union lost as many as 27 million people during the war, and 10 million of these were due to Nazi genocide. It is estimated that Poland lost up to six million people, and almost all of these were through genocide.

Once described by US President Herbert Hoover as "a great social and economic experiment", we now know that Prohibition was ultimately a failure, that led to increased crime and violence and gave way to a new era of mafia and mob influence in the United States. On January 17, 1920, the Volstead Act came into effect and the manufacturing, transportation, importation and sale of alcohol became federally prohibited across the United States, and while consumption was not a federal offence, it was sometimes prohibited on a state level. Opposition to Prohibition remained strong throughout the 1920s, and the Great Depression (starting in 1929) led many to advocate for the sale and taxation of alcoholic beverages in order to ease the US' economic woes. One of the reasons why Franklin D. Roosevelt was elected in 1932 was due to his promise of ending Prohibition, which he did with the Ratification of the 21st Amendment on December 5, 1933.

Impact on homicide rate

In the two decades before Prohibition, the recorded homicide rate in the United States was growing gradually, although often fluctuating in the 1910s. When Prohibition came into effect, the homicide rate continued on it's previous trajectory, but without fluctuating. While homicides related to alcohol consumption may have declined, some historians speculate that the total number could have continued to rise due to the increase in criminal activity associated with the illegal alcohol trade. The homicide rate in the US reached it's highest figure in the final year of Prohibition, with 9.7 homicides per 100,000 people in 1933, before falling to roughly half of this rate over the next ten years (this decrease in the early 1940s was also facilitated by the draft for the Second World War).

Impact on suicide rate

Alcohol's contribution to suicide rates has been significant throughout history, however it is only through more recent studies that society is beginning to form a clearer picture of what the relationship between the two actually is. In the first half of the twentieth century, there was no record of alcohol's role in individual suicide cases, however there was a noticeable change in the US' suicide rate during the 1920s. Prior to Prohibition, the suicide rate had already fallen from over 16 deaths per 100,000 people in 1915 to 11.5 in 1919, however this decline has been attributed to the role played by the First World War, which saw millions enlist and contribute to the war effort (a similar decrease can be observed in the lead up to the Second World War). After an initial spike in 1921, the suicide rate in the US then increases gradually throughout the 1920s, spiking again following the Great Depression in 1929. It is unclear whether the reduction in the US suicide rate in the 1910s and 1920s can be attributed to Prohibition, or whether it should be attributed to a variety of socio-economic factors, however the changing figures does suggest some correlation when compared with other decades.

The child mortality rate in Australia, for children under the age of five, was 391 deaths per thousand births in 1860. This means that just under forty percent of all children born in 1860 did not make it to their fifth birthday. This number dropped drastically over the next ten years, then it remained between 150 and two hundred for the remainder of the 1800s, before dropping consistently from 1900 until today. By 2020, child mortality in Australia is expected to be approximately four deaths per thousand births.