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 infant mortality rate in the United States, for children under the age of one (twelve months), was 60 deaths per thousand births in 1935. Approximately six percent of children born in 1935 did not survive past their first birthday. Over the course of the next 85 years, this number has dropped significantly, and the rate has reached its lowest point ever in the period between 2015 and 2020, at six deaths per thousand births. Figures have been below ten since the 1990s.

The infant mortality rate in Russia, for children under the age of one year old, was over 266 deaths per thousand births in 1870. This means that for all babies born in 1870, over one quarter did not survive past their first birthday. Unfortunately some information is missing in the early twentieth century, during Russia's revolutionary period and again during the Second World War, however it is noticeable that Russia's infant mortality rate fell to one death for every ten babies born in 1955, and from this point the rate has fallen to just six deaths per thousand births today.

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 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.

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.

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.

In the United States, the crude birth rate in 1800 was 48.3 live births per thousand people, meaning that 4.8 percent of the population had been born in that year. Between 1815 and 1825 the crude birth rate jumped from 46.5 to 54.7 (possibly due to Florida becoming a part of the US, but this is unclear), but from this point until the Second World War the crude birth rate dropped gradually, reaching 19.2 in 1935. Through the 1940s, 50s and 60s the US experienced it's baby boom, and the birth rate reached 24.1 in 1955, before dropping again until 1980. From the 1980s until today the birth rate's decline has slowed, and is expected to reach twelve in 2020, meaning that just over 1 percent of the population will be born in 2020.

A global phenomenon, known as the demographic transition, has seen life expectancy from birth increase rapidly over the past two centuries. In pre-industrial societies, the average life expectancy was around 24 years, and it is believed that this was the case throughout most of history, and in all regions. The demographic transition then began in the industrial societies of Europe, North America, and the West Pacific around the turn of the 19th century, and life expectancy rose accordingly. Latin America was the next region to follow, before Africa and most Asian populations saw their life expectancy rise throughout the 20th century.

The fertility rate of a country is the average number of children that women from that country will have throughout their reproductive years. In the United States in 1800, the average woman of childbearing age would have seven children over the course of their lifetime. As factors such as technology, hygiene, medicine and education improved, women were having fewer children than before, reaching just two children per woman in 1940. This changed quite dramatically in the aftermath of the Second World War, rising sharply to over 3.5 children per woman in 1960 (children born between 1946 and 1964 are nowadays known as the 'Baby Boomer' generation, and they make up roughly twenty percent of todays US population). Due to the end of the baby boom and increased access to contraception, fertility reached it's lowest point in the US in 1980, where it was just 1.77. It did however rise to over two children per woman between 1995 and 2010, although it is expected to drop again by 2020, to just 1.78.

For most of the past two centuries, falling birth rates have been associated with societal progress. During the demographic transition, where pre-industrial societies modernize in terms of fertility and mortality, falling death rates, especially among infants and children, are the first major change. In response, as more children survive into adulthood, women have fewer children as the need to compensate for child mortality declines. This transition has happened at different times across the world and is an ongoing process, with early industrial countries being the first to transition, and Sub-Saharan African countries being the most recent to do so. Additionally, some Asian countries (particularly China through government policy) have gone through their demographic transitions at a much faster pace than those deemed more developed. Today, in countries such as Japan, Italy, and Germany, birth rates have fallen well below death rates; this is no longer considered a positive demographic trend, as it leads to natural population decline, and may create an over-aged population that could place a burden on healthcare systems.

Life expectancy in India was 25.4 in the year 1800, and over the course of the next 220 years, it has increased to almost 70. Between 1800 and 1920, life expectancy in India remained in the mid to low twenties, with the largest declines coming in the 1870s and 1910s; this was because of the Great Famine of 1876-1878, and the Spanish Flu Pandemic of 1918-1919, both of which were responsible for the deaths of up to six and seventeen million Indians respectively; as well as the presence of other endemic diseases in the region, such as smallpox. From 1920 onwards, India's life expectancy has consistently increased, but it is still below the global average.

The World Health Organization (WHO) estimates that there were millions of smallpox cases every year until the 1970s, when the WHO's eradication program then successfully eliminated the disease in nature. Some academic estimates place smallpox's death toll at 300 million in the twentieth century, and 500 million in its final hundred years of existence. The development of the smallpox vaccination, which was the first successfully developed vaccine (the word vaccination comes from the Latin word for cow;"vacca", as cowpox was used to develop the smallpox vaccine), greatly contributed to the significant decline in infant and child mortality across the globe, and the boom in population growth during the twentieth century. Reported cases In spite of these large numbers, the figures for reported cases was only a tiny fraction of this; for example, the WHO estimates that there were fifty million cases in 1950, however less than one percent of these cases were recorded. In spite of this, the data is still useful for showing how smallpox developed and spread throughout the world; we know that the majority of these cases were recorded in the Indian sub-continent, and that epidemics across Asia drove the number of recorded cases up in the middle of the century. The final naturally-occurring cases were observed in 1977, while the two cases in 1978 were due to a lab accident in England, which resulted in one fatality.

Life expectancy in the United Kingdom was below 39 years in the year 1765, and over the course of the next two and a half centuries, it is expected to have increased by more than double, to 81.1 by the year 2020. Although life expectancy has generally increased throughout the UK's history, there were several times where the rate deviated from its previous trajectory. These changes were the result of smallpox epidemics in the late eighteenth and early nineteenth centuries, new sanitary and medical advancements throughout time (such as compulsory vaccination), and the First world War and Spanish Flu epidemic in the 1910s.

Life expectancy in Japan was 36.4 in the year 1860, and over the course of the next 160 years, it is expected to have increased to 84.4, which is the second highest in the world (after Monaco). Although life expectancy has generally increased throughout Japan's history, there were several times where the rate deviated from its previous trajectory. These changes were a result of the Spanish Flu in the 1910s, the Second World War in the 1940s, and the sharp increase was due to the high rate of industrialization and economic prosperity in Japan, in the mid-twentieth century.

The fertility rate of a country is the average number of children that women from that country would have throughout their reproductive years. In the United Kingdom in 1800, the average woman of childbearing age would have five children over the course of their lifetime. Over the next 35 years the fertility rate was quite sporadic, rising to over 5.5 in the 1810s and 1820s, then dropping to 4.9 by 1835. This was during and after the Napoleonic Wars and the War of 1812 with the US, which was a time of increased industrialization, economic depression and high unemployment after the war. As things became more stable, and the 'Pax Britannica' (a period of relative, international peace and economic prosperity for the British Empire) came into full effect, the fertility rate plateaued until 1880, before dropping gradually until the First World War. The fertility rate then jumped from 2.6 to 3.1 children per woman between 1915 and 1920, as many men returned from the war. It then resumed it's previous trajectory in the interwar years, before increasing yet again after the war (albeit, for a much longer time than after WWI), in what is known as the 'Baby Boom'. Like the US, the Baby Boom lasted until around 1980, where it then fell to 1.7 children per woman, and it has remained around this number (between 1.66 and 1.87) since then.

Life expectancy in China was just 32 in the year 1850, and over the course of the next 170 years, it is expected to more than double to 76.6 years in 2020. Between 1850 and 1950, finding reliable data proved difficult for anthropologists, however some events, such as the Taiping Rebellion and Dungan Revolt in the nineteenth century did reduce life expectancy by a few years, and also the Chinese Civil War and Second World War in the first half of the twentieth century. In the second half of the 1900s, Chinese life expectancy increased greatly, as the country became more industrialized and the standard of living increased.

Life expectancy in Canada was just below forty in the year 1800, and over the course of the next 220 years, it is expected to have increased by more than double to 82.2 by the year 2020. Throughout this time, life expectancy in Canada progressed at a steady rate, with the most noticeable changes coming during the interwar period, where the rate of increase was affected by the Spanish Flu epidemic and both World Wars.

The fertility rate of a country is the average number of children that women from that country will have throughout their reproductive years. In Germany in 1800, the average woman of childbearing age would have 5.4 children over the course of their lifetime. It remained around this number until the late 1820s, when it then dropped to just under five, which was a long-term effect of the Napoleonic Period in Europe. From this point until the end of the nineteenth century, Germany's fertility rate was rather sporadic, reaching it's lowest point in 1855 with an average of 4.6 births per woman, and it's highest point in 1875 (just after the foundation of the German Empire in 1871), with an average of 5.4 live births per woman. From the beginning of the twentieth century until the end of the Second World War, Germany's fertility rate dropped from around 5 children per woman in 1900, to 1.9 in 1945. The only time where the fertility rate increased was in the inter-war years. Like other countries heavily involved in the Second World War, Germany (both East and West) experienced a Baby Boom from the late 1940s to the late 1960s, however it then dropped to it's lowest point of just 1.3 children per woman by 1995, shortly after the re-unification of Germany. In recent years, Germany's fertility rate has gradually been increasing again, and is expected to reach 1.6 in 2020, its highest rate in over forty years.

The fertility rate of a country is the average number of children that women from that country will have throughout their reproductive years. In 1860, Canadian women of childbearing age would go on to have 5.7 children on average, however this number dropped significantly by 1925, where it was just 3.3. It then plateaued in the late 1920s, before dropping again, to 2.7 in 1940. Similarly to the United States, Canada experienced a large baby boom after the Second World War, rising to 3.9 in 1960, before declining again into the 1980s, and then plateauing between 1.5 and 1.7 until today. Canada's fertility rate is expected to be 1.5 children per woman in 2020.