I'm related to the Alexanders who lived in Parke Indiana in the 1840's before moving to Mahaska Iowa:
Susan M. C. Alexander (1813-after 1880)
Isabella Moore Alexander (1810-1895)
Mary Jane Alexander (1817-1880)
William M. Alexander (1811-1878)
I think there is another son as well per Isabella's obit.
Several of them married Henry siblings
William's daughter Mary Jane Alexander (1837-1899) married Elisha Shaw in Iowa and then moved to Turner county SD.