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 child mortality rate in China, for children under the age of five, was 417 deaths per thousand births in 1850. This means that for all children born in 1850, almost 42 percent did not make it to their fifth birthday. Over the course of the next 170 years, this number has dropped drastically, and the rate has dropped to its lowest point ever in 2020 where it is just twelve deaths per thousand births. The sharpest decrease came between 1950 and 1955, as the Chinese Civil War ended, and the country began to recover from the Second World War. The decline then stopped between 1955 and 1965, due to famines caused by Chairman Mao Zedong's attempted Great Leap Forward, which was a failed attempt to industrialize China in the late twentieth century.

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 New Zealand, for children under the age of five, was 391 deaths per thousand births in 1850. This means that just under forty percent of all children born in 1850 did not make it to their fifth birthday. This number dropped drastically over the next ten years, then it remained between one and two hundred for the remainder of the 1800s, before dropping gradually from 1900 until today. By 2020, child mortality in New Zealand is expected to be approximately five 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.

The child mortality rate in Germany, for children under the age of five, was 340 deaths per thousand births in 1800. This means that more than one in every three children born in 1800 did not make it to their fifth birthday. Child mortality increased to almost fifty percent in the mid-nineteenth century, as the country industrialized and urbanized rapidly, which allowed diseases to spread much faster. This changed however, with the introduction of mandatory vaccination in 1874, which kickstarted a gradual decline in child mortality in Germany. The decline was most rapid in the first half of the twentieth century, and by the year 2020 child mortality in Germany is expected to be as low as four deaths per thousand births.

The child mortality rate in Sweden, for children under the age of five, was 381 deaths per thousand births in 1800. This means that approximately 38 percent of all 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 from 1880 onwards, and the rate has dropped to its lowest point ever in 2020 where it is just two deaths per thousand births, which is the lowest in the world.

The child mortality rate in France, for children under the age of five, was 412 deaths per thousand births in 1800. This means that more than forty percent of all children born in 1800 did not make it to their fifth birthday. Child mortality remained high in the nineteenth century, before falling at a much faster rate throughout the 1900s. Despite falling consistently during the last 130 years, there were two occasions where child mortality actually increased, which can be attributed to both World Wars and the Spanish Flu Pandemic. In 2020, the child mortality rate in France is expected to be just four deaths per thousand births.

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.

The child mortality rate in Austria, for children under the age of five, was 387 deaths per thousand births in 1800. This means that just under forty percent of all children born in 1860 did not make it to their fifth birthday. Child mortality increased to over forty percent for most of the nineteenth century, as the country became more industrialized and urbanized, which allowed diseases to spread much faster. From 1900 onwards, the child mortality rate in Austria dropped consistently until today, (apart from a small increase during the Second World War) and it is expected to fall to just four deaths per thousand births in 2020.

The child mortality rate in Russia, for children under the age of five, was 419 deaths per thousand births in 1855. This translated into roughly 42 percent of all children born in 1855 not surviving past the age of five, and it remained above forty percent until the early twentieth century. Since then it has fallen consistently and it is expected to fall to its lowest recorded figure, at just seven deaths per thousand people in the period between 2015 and 2020. The spike in child mortality seen in the period between 1950 and 1955 is likely due to conflicting sources.

The infant mortality rate in Germany, for children under the age of one (twelve months), was 295 deaths per thousand births in 1840. This translated into approximately three out of every ten children born in 1840 not surviving past their first birthday. The largest decrease in this 180 year period came in the late 1870s, as Germany introduced mandatory vaccination for children, which brought infant mortality down by almost sixty in this five year period. From the turn of the twentieth century onwards, the infant mortality rate in Germany dropped considerably (although data in and immediately after the Second World War is not available), and by 2020 the number is expected to be just three deaths per thousand births.

For most of the world, throughout most of human history, the average life expectancy from birth was around 24. This figure fluctuated greatly depending on the time or region, and was higher than 24 in most individual years, but factors such as pandemics, famines, and conflicts caused regular spikes in mortality and reduced life expectancy. Child mortality The most significant difference between historical mortality rates and modern figures is that child and infant mortality was so high in pre-industrial times; before the introduction of vaccination, water treatment, and other medical knowledge or technologies, women would have around seven children throughout their lifetime, but around half of these would not make it to adulthood. Accurate, historical figures for infant mortality are difficult to ascertain, as it was so prevalent, it took place in the home, and was rarely recorded in censuses; however, figures from this source suggest that the rate was around 300 deaths per 1,000 live births in some years, meaning that almost one in three infants did not make it to their first birthday in certain periods. For those who survived to adolescence, they could expect to live into their forties or fifties on average. Modern figures It was not until the eradication of plague and improvements in housing and infrastructure in recent centuries where life expectancy began to rise in some parts of Europe, before industrialization and medical advances led to the onset of the demographic transition across the world. Today, global life expectancy from birth is roughly three times higher than in pre-industrial times, at almost 73 years. It is higher still in more demographically and economically developed countries; life expectancy is over 82 years in the three European countries shown, and over 84 in Japan. For the least developed countries, mostly found in Sub-Saharan Africa, life expectancy from birth can be as low as 53 years.

From the mid-19th century until today, life expectancy at birth in the United States has roughly doubled, from 39.4 years in 1850 to 79.6 years in 2025. It is estimated that life expectancy in the U.S. began its upward trajectory in the 1880s, largely driven by the decline in infant and child mortality through factors such as vaccination programs, antibiotics, and other healthcare advancements. Improved food security and access to clean water, as well as general increases in living standards (such as better housing, education, and increased safety) also contributed to a rise in life expectancy across all age brackets. There were notable dips in life expectancy; with an eight year drop during the American Civil War in the 1860s, a seven year drop during the Spanish Flu empidemic in 1918, and a 2.5 year drop during the Covid-19 pandemic. There were also notable plateaus (and minor decreases) not due to major historical events, such as that of the 2010s, which has been attributed to a combination of factors such as unhealthy lifestyles, poor access to healthcare, poverty, and increased suicide rates, among others. However, despite the rate of progress slowing since the 1950s, most decades do see a general increase in the long term, and current UN projections predict that life expectancy at birth in the U.S. will increase by another nine years before the end of the century.

Although vaccination was discovered in England in 1796, the practice was not made compulsory until 1853 in England and Wales, and 1864 in Scotland. For this reason, the number of smallpox deaths per million people fluctuated from year to year, often doubling or tripling from one year to the next, before the death rate for both countries settled in the late 1960s. The Great Pandemic of the 1870s, which was the last major smallpox pandemic in Europe, caused the number of smallpox deaths to soar once more, peaking at over 1,000 deaths per million people in England and Wales in 1871, and at over 820 deaths per million people in Scotland in 1872. During this pandemic, mandatory vaccination became enforced, where parents who did not vaccinate their children within the first three years of life were penalized with fines or imprisonment, and this helped the smallpox death rate to remain low and plateau in the final two decades of the nineteenth century; an estimated 11,000 of these penalties were handed out during the 1880s, which included 115 prison sentences for failure to vaccinate children. Smallpox cases in Britain were rare throughout the early twentieth century; not counting a lab accident in 1978 that infected two people (one of whom died), natural smallpox cases were eradicated in Britain in 1934.

The crude birth rate of Bosnia and Herzegovina has generally been in decline for the past 170 years. In 1850, there were approximately 41 births per thousand people, which meant that just over four percent of the population had been born in that year. The number then dropped to around 36 births per thousand until the 1940s (the steady decline from 1865 to 1945 suggests that these figures are averages for the entire period), until there was a slight baby boom in the aftermath of the Second World War, which peaked at 38 births per thousand in 1955. Following this boom, the fertility rate of Bosnia and Herzegovina then dropped at a much higher rate, falling to 9.5 births per thousand in 2005, and it has fallen to just eight births per thousand in 2020, which means that 0.8 percent of the population will be born this year. The reasons for this rapid decrease in birth rate was mostly due to reduced infant and child mortality, and improvements and increased access to healthcare, contraceptives and education, among other things.

In 1800, the population of Japan was just over 30 million, a figure which would grow by just two million in the first half of the 19th century. However, with the fall of the Tokugawa shogunate and the restoration of the emperor in the Meiji Restoration of 1868, Japan would begin transforming from an isolated feudal island, to a modernized empire built on Western models. The Meiji period would see a rapid rise in the population of Japan, as industrialization and advancements in healthcare lead to a significant reduction in child mortality rates, while the creation overseas colonies would lead to a strong economic boom. However, this growth would slow beginning in 1937, as Japan entered a prolonged war with the Republic of China, which later grew into a major theater of the Second World War. The war was eventually brought to Japan's home front, with the escalation of Allied air raids on Japanese urban centers from 1944 onwards (Tokyo was the most-bombed city of the Second World War). By the war's end in 1945 and the subsequent occupation of the island by the Allied military, Japan had suffered over two and a half million military fatalities, and over one million civilian deaths.

The population figures of Japan were quick to recover, as the post-war “economic miracle” would see an unprecedented expansion of the Japanese economy, and would lead to the country becoming one of the first fully industrialized nations in East Asia. As living standards rose, the population of Japan would increase from 77 million in 1945, to over 127 million by the end of the century. However, growth would begin to slow in the late 1980s, as birth rates and migration rates fell, and Japan eventually grew to have one of the oldest populations in the world. The population would peak in 2008 at just over 128 million, but has consistently fallen each year since then, as the fertility rate of the country remains below replacement level (despite government initiatives to counter this) and the country's immigrant population remains relatively stable. The population of Japan is expected to continue its decline in the coming years, and in 2020, it is estimated that approximately 126 million people inhabit the island country.

In 1800, the region of Germany was not a single, unified nation, but a collection of decentralized, independent states, bound together as part of the Holy Roman Empire. This empire was dissolved, however, in 1806, during the Revolutionary and Napoleonic eras in Europe, and the German Confederation was established in 1815. Napoleonic reforms led to the abolition of serfdom, extension of voting rights to property-owners, and an overall increase in living standards. The population grew throughout the remainder of the century, as improvements in sanitation and medicine (namely, mandatory vaccination policies) saw child mortality rates fall in later decades. As Germany industrialized and the economy grew, so too did the argument for nationhood; calls for pan-Germanism (the unification of all German-speaking lands) grew more popular among the lower classes in the mid-1800s, especially following the revolutions of 1948-49. In contrast, industrialization and poor harvests also saw high unemployment in rural regions, which led to waves of mass migration, particularly to the U.S.. In 1886, the Austro-Prussian War united northern Germany under a new Confederation, while the remaining German states (excluding Austria and Switzerland) joined following the Franco-Prussian War in 1871; this established the German Empire, under the Prussian leadership of Emperor Wilhelm I and Chancellor Otto von Bismarck. 1871 to 1945 - Unification to the Second World War The first decades of unification saw Germany rise to become one of Europe's strongest and most advanced nations, and challenge other world powers on an international scale, establishing colonies in Africa and the Pacific. These endeavors were cut short, however, when the Austro-Hungarian heir apparent was assassinated in Sarajevo; Germany promised a "blank check" of support for Austria's retaliation, who subsequently declared war on Serbia and set the First World War in motion. Viewed as the strongest of the Central Powers, Germany mobilized over 11 million men throughout the war, and its army fought in all theaters. As the war progressed, both the military and civilian populations grew increasingly weakened due to malnutrition, as Germany's resources became stretched. By the war's end in 1918, Germany suffered over 2 million civilian and military deaths due to conflict, and several hundred thousand more during the accompanying influenza pandemic. Mass displacement and the restructuring of Europe's borders through the Treaty of Versailles saw the population drop by several million more.

Reparations and economic mismanagement also financially crippled Germany and led to bitter indignation among many Germans in the interwar period; something that was exploited by Adolf Hitler on his rise to power. Reckless printing of money caused hyperinflation in 1923, when the currency became so worthless that basic items were priced at trillions of Marks; the introduction of the Rentenmark then stabilized the economy before the Great Depression of 1929 sent it back into dramatic decline. When Hitler became Chancellor of Germany in 1933, the Nazi government disregarded the Treaty of Versailles' restrictions and Germany rose once more to become an emerging superpower. Hitler's desire for territorial expansion into eastern Europe and the creation of an ethnically-homogenous German empire then led to the invasion of Poland in 1939, which is considered the beginning of the Second World War in Europe. Again, almost every aspect of German life contributed to the war effort, and more than 13 million men were mobilized. After six years of war, and over seven million German deaths, the Axis powers were defeated and Germany was divided into four zones administered by France, the Soviet Union, the UK, and the U.S.. Mass displacement, shifting borders, and the relocation of peoples based on ethnicity also greatly affected the population during this time. 1945 to 2020 - Partition and Reunification In the late 1940s, cold war tensions led to two distinct states emerging in Germany; the Soviet-controlled east became the communist German Democratic Republic (DDR), and the three western zones merged to form the democratic Federal Republic of Germany. Additionally, Berlin was split in a similar fashion, although its location deep inside DDR territory created series of problems and opportunities for the those on either side. Life quickly changed depending on which side of the border one lived. Within a decade, rapid economic recovery saw West Germany become western Europe's strongest economy and a key international player. In the east, living standards were much lower, although unemployment was almost non-existent; internationally, East Germany was the strongest economy in the Eastern Bloc (after the USSR), though it eventually fell behind the West by the 1970s. The restriction of movement between the two states also led to labor shortages in t...

Throughout the Common Era, Japan's population saw relatively steady growth between each century. Failed invasions and distance from Asia's mainland meant that Japan was unaffected by many pandemics, primarily bubonic plague, therefore its development was not drastically impeded in the same way as areas such as China or Europe. Additionally, religious practices meant that hygiene was prioritized much more in Japan than in other regions, and dietary customs saw lower rates of meat consumption and regular boiling of water in meals or tea; both of these factors contributed to lower rates of infection for many parasitic or water-borne diseases. Fewer international conflicts and domestic stability also saw lower mortality in this regard, and Japan was an considered an outlier by Asian standards, as some shifting trends associated with the demographic transition (such as lower child mortality and fertility) began taking place in the 17th century; much earlier time than anywhere else in the world. Yet the most significant changes came in the 20th century, as Japan's advanced healthcare and sanitation systems saw drastic reductions in mortality. Challenges Japan's isolation meant that, when pandemics did arrive, the population had less protection and viruses could have higher mortality rates; smallpox has been cited as the deadliest of these pandemics, although increased international contact in the late 19th century brought new viruses, and population growth slowed. Earlier isolation also meant that crop failure or food shortages could leave large sections of the population vulnerable, and, as mentioned, the Japanese diet contained relatively little meat, therefore there was a higher reliance on crops and vegetables. It is believed that the shortage of arable land and the acidity of the soil due to volcanic activity meant that agriculture was more challenging in Japan than on the Asian mainland. For most of history, paddy fields were the most efficient source of food production in Japan, but the challenging nature of this form of agriculture and changes in employment trends gradually led to an increased reliance in imported crops. Post-Sakoku Japan Distance from the Asian mainland was not the only reason for Japan's isolation; from 1603 to 1853, under the Tokugawa shogunate, international trade was restricted, migration abroad was forbidden, and most foreign interaction was centered around Nagasaki. American neo-imperialism then forced Japan to open trade with the west, and Japan became an imperial power by the early-1900s. Japanese expansion began with a series of military victories against China and Russia at the turn of the century, and the annexation of Taiwan, Korea, and Manchuria by the 1930s, before things escalated further during its invasion of China and the Second World War. Despite its involvement in so many wars, the majority of conflicts involving Japan were overseas, therefore civilian casualties were much lower than those suffered by other Asian countries during this time. After Japan's defeat in 1945, its imperial ambitions were abandoned, it developed strong economic ties with the West, and had the fastest economic growth of any industrial country in the post-WWII period. Today, Japan is one of the most demographically advanced countries in the world, with the highest life expectancy in most years. However, its population has been in a steady decline for over a decade, and low fertility and an over-aged society are considered some of the biggest challenges to Japanese society today.