The founding of the German Empire was not a single act which could be clearly distinguished from others. There are several definitions in literature which can be divided into four periods. However, authors are not always consistent with their distinctions. It also originated from the specific theme or structure of publication. It is not, in itself, a contradiction, on the one hand, to speak of a chronologically very limited foundation of the German Empire in 1871. On the other hand, often a "Reichgründungsepoche", or "Age of the German Founding" is spoken of, which can often be classified with the German revolutions of 1848 and 1849.
Michael Stürmer concentrated on Bismarck in his "Die Reichsgründung" and the years 1866 to 1878 (from the Austro-Prussian War to the Congress of Berlin). It dates back however to the Holy Roman Empire. The actual historic event begins in 1848/1849. The result of the revolution was a "hovering state", "no return to that order which had collapsed like a map house in March 1848, a blockade of central European nationalisation". The "Reichsgründungsepoche" ended during the second half of the 1870s, according to Stürmer with the foreign policy concerning the consolidation of the Empire. Similar to Stürmer, Frank Lorenz Müller posed the same question with clearly answering it:
"Effective 1848/49, at the beginning of a period of transformation between 1845 and 1871, which brought the breakthrough of political, economic and social modernity? [...] In the summer of 1849, the victory of the counter-revolution had caused neither deadly stagnation nor cemetery rest. Germany remained in a state of flux"
— Franz Lorenz Müller
The "Founding of the German Empire" was briefly described at the turn of the 1870 into 1871. Ernst Rudolf Huber describes the time from the imperial plan of 1870 on the beginning of wain in July, the so-called November Treaties, the constitution of the German Confederation from 1 January, "the establishment of the imperial organs", including the imperial proclamation and the Reichstag election in March until the new constitution of April 1871. It was precisely the imperial proclamation of 18 January 1871 that "in the minds of the Germans, the actual Reichsgründungsakt remained", says Theodor Schieder. Andreas Kaernbach complains that:
"In understandable joy about the founding of the German Empire [...] the time of the German and the North German Confederation appeared to many as merely a pre-history of the foundation of the Empire, as a transitory stage, but not as an epoch of its own historical weight."
— Andreas Kaernbach
Various publications include the North German Confederation and its immediate past history. Then, there were the years of 1866 and 1871. A decisive event was the Prussian victory at Hradec Kralove, which ended the Austro-Prussian dualism. The Second Schleswig War (1864 - Einigungskriege") was accepted as a starting point. Some authors claim the start to be the "Reichsgründungsjahrzehnt" (Decade of the Founding of the German Empire) when the German National Association was founded in 1859. In the prolongation until 1878, others also speak of the Liberal era. The years around 1878 are also called the "Second Founding of the German Empire" because a new "alliance between harrow and furnace" was formed between entrepreneurs of heavy industry and the feudal elite.
Other authors also speak of a "Reichsgründungszeit" or "Reichsgründsungsepoche" (Time of the Founding of the Empire), or of a "way to founding the empire", meaning the period between 1848/49 and 1871. Christian Jansen sees the revolutions of 1848/49 as being the "initial firing for the establishment of the founding of the national state" also because of political parties being formed at that time. In this view, the Frankfurt Constitution of 1849 was recognised as the first attempt at reconciliation. In the period between 1848 and 1866/1871, dualism was recognised as a problem for the formation of national states and (by war) solved just as much as the First Schleswig War. Bismarck was active politically in 1848/49 and had proven himself to be concerned with the constitutions of the time. The road to the Erfurt Union, with the election of a constituent assembly agreed by the princes, was the model used to found the Federal German Republic in 1867.