Genealogy / Ownership of Land 1890 [2]

I was told my great-grandfather (Adam Blak 1840-1895) who was originally a blacksmith, bought land to become a farmer. His father in-law (Aleksander KOŁAKOWSKI 1817-1899) it is my understanding owned land in several villages. The town closest to Adam's farm was Przywilcz, it is located north of Ciechanów and east of Mława south of Grudusk and west of Czernice Borowe. Could this be true? Could ordinary citizens own land, or were they all just serfs to the Czar?