That is in Macoupin County, which is in Southwestern Illinois. In 1850, Isaac Beckett (41) and his family [Nancy (36), John (17), Isaac (14); Julia (16?, probably 13), George (12), Wm. (10), Amy (8), Hy (?) 7, Sheba (5), Nancy (3), Mary (1)] moved from Ohio to Champaign County, Illinois. In 1860, they were living in Jubille Township, Peoria County, Illinois. Those counties are more in the east central part of Illinois. I lost track of them after 1860. It is quite possible that one or more of their children relocated more westward toward Macoupin County. I will check this out and let you know if I find anything. I suggest you get the death certificate for Dennis Beckett because it should list who his parents were.
Regards, Bill The fellow who leans on his family tree may never get out of the woods.