In 1815, after the Napoleonic turmoil which overcame the draconian verdict of the partitions for several years, a large part of Greater Poland including Poznań and Bydgoszcz was again incorporated into the Prussian state. By the decision of king Frederick William III, this time it gained the status of the Grand Duchy of Poznań, which, in pursuance of the provisions of the Vienna Congress, was supposed to ensure a certain set of rights to the Polish population, expressed above all in the equal treatment of the Polish language in both administration and schooling. Throughout the entire 19th century, Poles were supposed to dominate here in numbers, constituting about two third of the Duchy's population; their prevalence was particularly visible in the countryside, while in cities, especially the larger ones, the economically strong German and Jewish population was dominant. If, however, in other parts of Prussia inhabited by Poles - Silesia or Warmia and Masuria - the Polish community consisted of exclusively peasants, in the Poznań region, they were led by elites, initially originating from noblemen and then, to a greater and greater extent, from the intelligentsia, which were aware of their national and political objectives and which maintained the memory of the former Republic of Poland and the idea of Polish independence. Declarations made in 1815 by the Prussians, regarding respect for the Polish nationality, were then received with a certain distance, still glancing towards Warsaw and hoping that the Duchy would be integrated with the Polish Kingdom, so when the November Uprising broke out in 1830, about 3000 Poznań inhabitants took part in it.

The Polish distrust in relation to the Prussian promises was in fact justified, as from the point of view of Berlin, the Great Duchy of Poznań was a province of great military and geopolitical significance; it connected the southern and central parts of the Hohenzollern's monarchy with its north-eastern borderlands: Pomerania and East Prussia. Therefore, despite the initial declarations, Berlin's objective was its full integration within the Prussian state. It gained even more significance after the November Uprising, when the use of the Polish language began to be consequently limited in public life and in gymnasium education, and official posts were only granted to Germans. At the same time the authorities started a number of modernisation projects, including an intensification of the process of granting freehold to peasants initiated in 1823, the establishment of public schools and the construction of roads, which was supposed to make the Polish population accept the higher German civilisation. This was a new challenge for the Polish elites who had experienced the disaster of the November Uprising and were at the same time aware of the growing German threat and the inevitability of civilizational changes. In this situation, other ideas started to appear: long-lasting, systematic work on the economic, cultural and organisational rise of Polish society, which in the year 1848 would acquire the name of “organic work” as coined by Poznań journalism. The first institution, which we currently refer to as organicist, was the “Kasyno” in Gostyń established by land-owners in the year 1835. However, the most long-lasting institutions of this type were founded from the inspiration of the Poznań physician, the true leader of the Polish community in the Poznań region at that time - Karol Marcinkowski. And so, in the year 1841, the Bazar Hotel was opened in the capital city of the province. Polish merchants and carpenters ran their shops there and many political and cultural events or meetings of Polish organisations subsidised in certain cases from the hotel profits were held in the rooms of the hotel. Of great significance was the establishment of the true foundation of Polish national activity in 1841 - the Scientific Help Society, a scholarship organisation which collected funds for the education of the Polish youth, without which it would be difficult to imagine the existence of a Polish intelligentsia in the Poznań region, which was to take over the leadership of the Polish matters in the 19th century. As well as the first organicist institutions, the democratic conspiracy of the so called Poznań Central Board (Centralizacja) developed in 1840s covering wide land-owner and intelligentsia circles and intending to trigger a tri-partition uprising; however this greatest conspiratorial project of the first half of the 19th century was uncovered in the Poznań region and hundreds of its members went to prison, while most other organisations which had been established before, such as e.g. “Kasyno” in Gostyń, were dissolved. Only the Scientific Help Society survived. The conspirators sentenced in the so called Great Trial in Berlin, were freed as a result of the Revolutions of 1848 (Spring of Nations), which stimulated the establishment of the Polish National Committee in Poznań. The Committee demanded broad autonomy for the Grand Duchy (so called national reorganisation). In that revolutionary atmosphere King Frederick William IV not only gave his preliminary consent to this but also allowed for the formation of Polish military troops in the Poznań region, whose task was to counteract the expected Russian intervention together with the Prussian army, though the commander of those troops, Ludwik Mierosławski, saw them as the foundation of a Polish army which would liberate all Polish territories and lead to the rebirth of the independent Polish state. This, however, did not happen - the Prussians attacked the Polish camp in Książ massacring its defenders; despite the honorary victories near Miłosław and Sokołów, the Poles had to lay down their weapons, many of them spent a certain period of time imprisoned in a fortress, and those who did not get there, faced all kinds of humiliations and persecutions. What was most surprising for them was the fact that a sizeable part of the local German and Jewish population actively opposed the Polish national aspirations; the Polish problem was no longer just an issue of the state's policy, but rather it started to take on the dimension of a nationality-based conflict.

The loss of hope related to the European outbreak of freedom aspirations in the year 1848 did not suppress the energy that was freed in the previous years. It found an outlet in two complementary types of activity which were to determine the Polish activities for the next few decades; as well as a reactivated organicist programme, there was now also parliamentary activity. The latter resulted from the granting of a constitution to Prussia and the convening of the parliament (sejm) - Landtag in Berlin in which also Polish members of parliament elected by voters of the Polish community and representing its aspirations and interests sat. Gathered since 1849 in the Polish Circle, which after the unification of Germany in 1871, was also established in the Parliament of the Reich (Reichstag), they tried to defend the Polish nationality from the parliamentary tribune and publicly stigmatise the violations of the rights, to which they were entitled. Elections to both parliamentary bodies were an opportunity for the mobilisation of the Polish community within the entire partition to articulate its aspirations and internal integration; they also forced out the creation of a network of associations covering the entire Polish community, and allowing for effective electoral action. The political activity in parliament was complemented by the return to the organic work programme; it was not an accident that, after all, this term was actually introduced into the language of the Polish public debate, in the year 1848. This time, it was expressed in the broad formula of the Polish League which was supposed to concentrate the entire Polish national activity. Indeed, in the initial period, the League developed dynamically not only in the Poznań region, but also in Gdańsk Pomerania, however in the year 1850, the Prussians brought it down using legal measures. A new stage of the development of the organicist system started at the beginning of 1860s and the general social stir on Polish territories before the January Uprising also had a certain influence on this. Poznań inhabitants gave their lives in military operations during the Uprising per se, the district was an important base for the insurgent movement during a certain period of time. After the defeat, the Poznań elites were well prepared to undertake organicist activity again, without even trying to create, this time, a single big structure with one general national objective, but rather organisations specialised in some kind of an activity, which could not be questioned under Prussian law. And so the Polish landed gentry organised itself within the framework of the Central Economic Society, peasants formed agricultural circles which developed dynamically for many years under the supervision of their patron - Maksymilian Jackowski. Industrial Societies began to establish themselves in cities, and from the middle of 1880s, the Polish Gymnastic Society Sokół which promoted Polish national awareness more than just physical culture. Earning associations were extremely important as they provided capital for the modernisation of workshops, shops or farms. In 1871 they were united as the Union of Earning Associations under the patronage of a vicar from Środa, Priest Augustyn Szamarzewski. Their next patron, Priest Piotr Wawrzyniak, a true economic and organisational genius, contributed to their heyday in the end of the 19th century and the beginning of the 20th century. Educational activity was at first the main focus of the People's Education Society, then the People's Libraries Society and the Warta Society headed by Aniela Tułodziecka, one of the leading representatives of the more and more socially active women. An important role was played by the Polish press, first and foremost, the ”Dziennik Poznański” and the ”Kurier Poznański” and from 1890s, the ”Przewodnik Katolicki”, which was published in mass circulation. This allowed for effective resistance against a new wave of Germanisation, the harbinger of which was the Kulturkampf policy which compromised the Polish church and education in 1870s, and from the year 1886, an organised policy aimed at changing the national image of eastern provinces. Its tool was the Settlement Commission, a governmental agency dealing with the German settlement in the Poznań region and West Prussia. However, the more and more drastic anti-Polish measures did not bring the expected results from the German point of view. At the turn of the 19th and 20th century, the Poles living in the Poznań region formed a cohesive and well organised community, which entered the cities more and more boldly and competed with the Germans and the Jews effectively. The changes in the profile of the Polish community were also accompanied by a generational change of the guard, symbolised by the national democracy which was rising in force and which politically dominated the image of the Polish community in this district, remaining in close contact with other partitions. At the same time, Prussian pressure forced out new forms of activity and protest; the school strikes in the years 1901 and 1906, which involved thousands of Polish children in defence of prayer in their native tongue, the last remnant of the Polish language in the thoroughly germanised school system, were echoed throughout Europe. A symbol of the persistent fight for land was the resistance of Michał Drzymała who lived in a circus caravan as a protest against not receiving a permit to build a house on his own land. Under these conditions, the young generation, not so much attached to the existing Poznań legalism began to take the floor in defence of Polish nationality. In 1912, the first underground scout groups were established in Poznań. In the following year, in front of the monument of Adam Mickiewicz, clashes between young Polish demonstrators and the police took place. The young Poles were beginning to lose patience. Five years later, they would form the staff of the Greater Poland Uprising.