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.

In Germany, the crude birth rate in 1800 was 38 live births per thousand people, meaning that 3.8 percent of the population had been born in that year. In the nineteenth century, Germany's crude birth rate fluctuated between 34 and 40 births per thousand people. Since the turn of the twentieth century however, the crude birth rate has been in decline, although there were a few periods where it did increase. These increases took place during periods of economic recovery, after both world wars, and after the Great Depression. The largest period of increase was after the Second World War, and lasted until the late 1960s, before decreasing to 10.3 in 1980, where it then plateaus between eight and eleven, and it is expected to be 9.4 births per thousand people in 2020.

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.

The study’s theme: The development of infant mortality in Germany for the 19th century is only poorly documented. Especially for the period prior to 1871 only small area statistics are available. With the preparation of the information collected by the authorities of the former German States the author tries to create a new statistical basis. The reconstructed national series of birth and infant mortality (from 1826) documents relatively high infant mortality rates with little progress (i.e. improvement of the situation) until the beginning of the 20th Century. Considering the influence of urbanization the evaluation of the different regional patterns and trends leads to a new weighting of the problem. Thus the living and working conditions in the country were of considerable importance. Overall, the prevailing habits and attitudes are considered crucial to the survival of small children (Gehrmann 2011, S. 807)

Data and data preparation, source problems: The federal structure of the Empire leads to the problem that the printed statistics on infant mortality before 1901 remained incomplete. In some German states, information concerning infant mortality was not collected from the beginning of the registry offices. However, the ‘Kaiserliches Statistisches Amt’ (Imperial Statistical Office) was able to create despi9te the difficult situation a life table, which represented 97,3% of live birth for the period of 1872 to 1880. Hence, the annual infant mortality rate in 1872 is known. „Die föderale Struktur des Kaiserreichs hatte (…) zur Folge, dass die gedruckte Statistik zur Säuglingssterblichkeit vor 1901 lückenhaft blieb. Mehr noch: es wurden offensichtlich in einigen Staaten diesbezügliche Angaben gar nicht oder zumindest nicht von Anfang an bei den Standesämtern abgefragt. Als das Kaiserliche Statistische Amt in den 1880er Jahren die erste Sterbetafel für das Deutsche Reich erstellen wollte, musste es deshalb konstatieren, dass in den Einzelstaaten „fast alle in der Statistik überhaupt üblichen Arten und Grade der Spezialisierung vertreten“ (Kaiserliches Statistisches Amt 1887: 21) waren, aus manchen aber trotzdem keine geeigneten Unterlagen beschafft werden konnten. Immerhin repräsentierte die Sterbetafel am Ende doch 96,8% der Reichsbevölkerung im Jahre 1885 und 97,3% der Lebendgeborenen 1872 bis 1880. Damit ist auch die jährliche Säuglingssterblichkeitsrate ab 1872 bekannt. (…) Mit Hilfe des Sterbetafel-Materials kann die statistische Reihe aus „Bevölkerung und Wirtschaft“ also um fast 30 Jahre nach hinten verlängert werden. (…) Komplizierter stellt sich die Sachlage für weiter zurückliegende Zeitabschnitte dar. „ (S. 812-813) Although in most German states statistical collection on population movement has been carried out, the statistics vary considerably in quality. In the first step therefore, the author reject the procedure of simply extrapolating the birth rates because of the qualitative differences of the early statistics are too fundamental. Especially, in this approach of simply summing up, the values of the undocumented areas would equate with the values of the other well documented regions. Therefore, the author chose a complex way to estimate the lacking values: The missing values in small territories are estimated on the basis of the values of neighboring regions. Finally, it can be seen, that the data for the period from 1828 to 1871, calculated by the complex procedure of filling in missing data does not lead to significantly different results comparing to the data row calculated by the simple sum of the different sources. Per year, the difference between the two series (the series calculated in the complex way and the series calculated by summing up the values of the available statistics) is not more than 0,9 percent points, which can be seen as a slight difference between the two series in relation to the former level of infant mortality. The indeterminate values of those German states lacking a birth statistics may not being significantly different to those calculated on the basis of the complex procedure, because even unexpected, extreme runaway values in individual states can not realistically assumed to be so large that they could have a sufficient impact on the overall values. Thus, the presented row is a solid basis for the assessment of the overall development of the German Empire’s birth development. „Vielmehr empfiehlt es sich, zunächst in kleinen Schritten für die einzelnen Territorien fehlende Werte durch wahrscheinliche zu ersetzen. Diese ergeben sich in erster Linie aus dem Vergleich der Säuglingssterblichkeitswerte benachbarter Gebiete zu anderen Zeitpunkten. So können für Württemberg die vor 1859 zu längeren Zeiträumen zusammengefassten Informationen auf Einzeljahre herunter gerechnet werden, indem die Verteilung über die Jahre wie in Bayern angenommen wird. … Alle ermittelten Werte beziehen sich auf Lebendgeborene.“ (S. 814) „Die komplexe Prozedur der Ergänzung...

In the past four centuries, the population of the United States has grown from a recorded 350 people around the Jamestown colony of Virginia in 1610, to an estimated 331 million people in 2020. The pre-colonization populations of the indigenous peoples of the Americas have proven difficult for historians to estimate, as their numbers decreased rapidly following the introduction of European diseases (namely smallpox, plague and influenza). Native Americans were also omitted from most censuses conducted before the twentieth century, therefore the actual population of what we now know as the United States would have been much higher than the official census data from before 1800, but it is unclear by how much. Population growth in the colonies throughout the eighteenth century has primarily been attributed to migration from the British Isles and the Transatlantic slave trade; however it is also difficult to assert the ethnic-makeup of the population in these years as accurate migration records were not kept until after the 1820s, at which point the importation of slaves had also been illegalized. Nineteenth century In the year 1800, it is estimated that the population across the present-day United States was around six million people, with the population in the 16 admitted states numbering at 5.3 million. Migration to the United States began to happen on a large scale in the mid-nineteenth century, with the first major waves coming from Ireland, Britain and Germany. In some aspects, this wave of mass migration balanced out the demographic impacts of the American Civil War, which was the deadliest war in U.S. history with approximately 620 thousand fatalities between 1861 and 1865. The civil war also resulted in the emancipation of around four million slaves across the south; many of whose ancestors would take part in the Great Northern Migration in the early 1900s, which saw around six million black Americans migrate away from the south in one of the largest demographic shifts in U.S. history. By the end of the nineteenth century, improvements in transport technology and increasing economic opportunities saw migration to the United States increase further, particularly from southern and Eastern Europe, and in the first decade of the 1900s the number of migrants to the U.S. exceeded one million people in some years. Twentieth and twenty-first century The U.S. population has grown steadily throughout the past 120 years, reaching one hundred million in the 1910s, two hundred million in the 1960s, and three hundred million in 2007. In the past century, the U.S. established itself as a global superpower, with the world's largest economy (by nominal GDP) and most powerful military. Involvement in foreign wars has resulted in over 620,000 further U.S. fatalities since the Civil War, and migration fell drastically during the World Wars and Great Depression; however the population continuously grew in these years as the total fertility rate remained above two births per woman, and life expectancy increased (except during the Spanish Flu pandemic of 1918).

Since the Second World War, Latin America has replaced Europe as the most common point of origin for migrants, with Hispanic populations growing rapidly across the south and border states. Because of this, the proportion of non-Hispanic whites, which has been the most dominant ethnicity in the U.S. since records began, has dropped more rapidly in recent decades. Ethnic minorities also have a much higher birth rate than non-Hispanic whites, further contributing to this decline, and the share of non-Hispanic whites is expected to fall below fifty percent of the U.S. population by the mid-2000s. In 2020, the United States has the third-largest population in the world (after China and India), and the population is expected to reach four hundred million in the 2050s.

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.

At the beginning of the 19th century, the area of modern-day Italy, at the time a collection of various states and kingdoms, was estimated to have a population of nineteen million, a figure which would grow steadily throughout the century, and by the establishment of the Kingdom of Italy in 1861, the population would rise to just over 26 million.

Italy’s population would see its first major disruption during the First World War, as Italy would join the Allied Forces in their fight against Austria-Hungary and Germany. In the First World War, Italy’s population would largely stagnate at 36 million, only climbing again following the end of the war in 1920. While Italy would also play a prominent role in the Second World War, as the National Fascist Party-led country would fight alongside Germany against the Allies, Italian fatalities from the war would not represent a significant percentage of Italy’s population compared to other European countries in the conflict. As a result, Italy would exit the Second World War with a population of just over 45 million.

From this point onwards the Italian economy started to recover from the war, and eventually boomed, leading to increased employment and standards of living, which facilitated steady population growth until the mid-1980s, when falling fertility and birth rates would cause growth to largely cease. From this point onward, the Italian population would remain at just over 57 million, until the 2000s when it began growing again due to an influx of migrants, peaking in 2017 at just over 60 million people. In the late 2010s, however, the Italian population began declining again, as immigration slowed and the economy weakened. As a result, in 2020, Italy is estimated to have fallen to a population of 59 million.

In 1800, the population of the area of modern-day Hungary was approximately 3.3 million, a figure which would steadily rise in the first two decades of the 19th century, as modernization driven by rising exports of cash crops resulting from the ongoing Napoleonic wars would see Hungary become a major exporter in Europe. The slowing in population growth in the 1920s can be attributed in part to the economic recession which hit Hungary in the years following Napoleon defeat, as a grain prices collapsed, and economic hardship intensified in the country. Hungary would see a small increase in population growth in the 1860s, as the country would merge with the Austria to form Austria-Hungary in 1967. As industrialization would continue to accelerate in Hungary, the country’s population rise even further, reaching just over seven million by 1900.

While Hungary had enjoyed largely uninterrupted growth throughout the 19th century, the first half of the 20th century would see several major disruptions to Hungary’s population growth. Growth would slow greatly in the First World War, as Austria-Hungary would find itself one of the largest combatants in the conflict, losing an estimated 1.8 to 2 million people to the war. Hungary’s population would flatline entirely in the 1940s, as the country would see extensive military losses in the country’s invasion of the Soviet Union alongside Germany, and further loss of civilian life in the German occupation of the country and subsequent deportation and mass-murder of several hundred thousand Hungarian Jews. As a result, Hungary’s population would remain stagnant at just over nine million until the early 1950s.

After remaining stagnant for over a decade, Hungary’s population would spike greatly in the early 1950s, as a combination of a tax on childlessness and strict contraception restrictions implemented by then-Minister of Public Welfare Anna Ratkó would lead to a dramatic expansion in births, causing Hungary’s population to rise by over half a million in just five years. However, this spike would prove only temporary, as the death of Stalin in 1953 and subsequent resignation of much of the Stalinist regime in Hungary would see an end to the pro-natalist policies driving the spike. From 1980 onward, however, Hungary’s population would begin to steadily decline, as a sharp reduction in birth rates, combined with a trend of anti-immigrant policies by the Hungarian government, both before and after the collapse of the Soviet bloc, has led Hungary’s population to fall steadily from its 10.8 million peak in 1980, and in 2020, Hungary is estimated to have a population of just over nine and a half million.