Сувалкская губерния
According to Russian statistics from 1889, there were 57.8% Lithuanians, 19.1% Poles, and 3.5% Belarusians in the Suwałki Governorate. It is generally agreed that Lithuanians formed the majority of the population in the northern Suwałki Governorate, while Poles were concentrated in the south. But Lithuanian and Polish historians and political scientists continued to disagree over the location of the line that separated the areas of Lithuanian and Polish majorities. Lithuanians claimed that Sejny and the surrounding area were inhabited primarily by the Lithuanians, while the Poles claimed exactly the opposite. The German census of 1916 showed that 51% of Sejny population was Lithuanian.