Due to the intellectual and artistic climate of the early 19th century, which included the great composer Chopin, there was a “growth of Polish demands for self-government.” Armed rebellion, though, was ultimately unsuccessful. The latter part of this period was also a time of a large Polish emigration, largely to the United States.
Now, I grew up in Binghamton, a small upstate New York city with a fairly sizable eastern European population. So not only did I think these imperialistic actions were terribly unfair, I recognized, even then, that the changing boundaries of a country must wreak havoc on anyone trying to do any type of genealogical research.
Poland was reborn as an independent nation after World War I. However, after the second World War, “the allies decided then that the eastern parts of Poland would be passed on to the republics of the Soviet Union. The large cities… were ethnically predominantly or almost exclusively Polish… After 1945 most of the “eastern” Poles were forced to resettle into the present area of Poland and especially into its new western territories which in turn had been cut off from the ‘old’ Germany.”
Here’s a 100-second video showing Poland’s changing borders over the centuries.