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.

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 *** 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 ** 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.

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.

Even in 2021, bubonic plague continues to exist in nature, and there are generally a few thousand human cases per year. Going back to the beginning of the 20th century, it is estimated that there were roughly one million cases per year in 1907. Within two decades, this number had fallen below one fifth of this level to 170,000 cases per year in the 1920s, and in the 1940s it was just over 20,000 per year. By the mid-20th century, it had fallen below 5,000 cases per year, but the rapid decrease in cases observed in the first half of the 1900s did not continue through the second half of the century. Even in 2019, there was one case of plague recorded in the United States. How infection occurs Yersinia pestis is the bacteria that causes the plague virus, and it is most commonly spread by rats and their fleas. The disease survives by fleas infecting rats, which in turn infect other fleas; the majority of rats survive the disease, which facilitates its spread; this is known as the "enzootic cycle ". Interestingly, the disease is usually fatal for the fleas, as it blocks their "stomachs" and causes them to starve; as the fleas get hungrier, they attempt to feed on more hosts, spreading the disease more rapidly. When the rats die, the parasitic fleas then search for a new host, which means that other animals (particularly mammals) are susceptible to this virus. While rat fleas can not survive on other hosts for very long, they can infect other (including human) fleas with the virus. The most common way for humans to contract the plague however, is when a rat flea bites its human host; during this process the flea simultaneously regurgitates Yersinia pestis bacteria into the wound, and this causes bubonic plague. Humans can then spread the disease among one another by coming into contact with the infected tissue or fluids of an infected person, or from the transfer of fleas. Continued existence of the plague Plague is extremely difficult to eradicate in nature, as rodent communities in the wild provide natural reservoirs for the disease to spread. In previous centuries, rats had much more frequent contact with humans for a variety of reasons; houses were more often made of wood (which made infestations easier), public spaces were much dirtier, and the presence of rats was tolerated more. As the understanding of epidemiology grew in the 20th century, this greatly reduced the frequency of plague in human populations. Unlike human diseases such as smallpox, which was eradicated through vaccination and other medical advancements, basic sanitation and the extermination of rats have been the driving force behind the decline of plague.

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.

Since the 1950s, the suicide rate in the United States has been significantly higher among men than women. In 2022, the suicide rate among men was almost four times higher than that of women. However, the rate of suicide for both men and women has increased gradually over the past couple of decades. Facts on suicide in the United States In 2022, the rate of suicide death in the United States was around 14 per 100,000 population. The suicide rate in the U.S. has generally increased since the year 2000, with the highest rates ever recorded in the years 2018 and 2022. In the United States, death rates from suicide are highest among those aged 45 to 64 years and lowest among younger adults aged 15 to 24. The states with the highest rates of suicide are Montana, Alaska, and Wyoming, while New Jersey and Massachusetts have the lowest rates. Suicide among men In 2023, around 4.5 percent of men in the United States reported having serious thoughts of suicide in the past year. Although this rate is lower than that of women, men still have a higher rate of suicide death than women. One reason for this may have to do with the method of suicide. Although firearms account for the largest share of suicide deaths among both men and women, firearms account for almost 60 percent of all suicides among men and just 35 percent among women. Suffocation and poisoning are the other most common methods of suicide among women, with the chances of surviving a suicide attempt from these methods being much higher than surviving an attempt by firearm. The age group with the highest rate of suicide death among men is by far those aged 75 years and over.