Crawford and Franklin Co, Arkansas Township Changes from 1830 to 1840 In 1830 the Crawford County Census had seven townships: Big Creek, Upper, Richland, Lee's Creek, Mulberry, Horsehead and Lower.

In Dec 1837, Franklin County was created out of Crawford.

Big Creek, Upper, Richland, and Lee's Creek stayed in Crawford.
Horsehead went to the newly-formed Johnson Co (formed in 1833).
That left Mulberry and Lower to form Franklin Co (formed Dec 1837).

To these two townships, were added Boston and Prairie in 1838 and White Oak sometime before this.

Evidently White Oak existed prior to 1838, but exactly when it was created is not recorded in the Franklin Co County Court Minutes

County and Probate Court Minutes, Franklin Co, Arkansas
16 Apr 1838
On petition ordered that the Township of White Oak be divided [describes a line]. And that the territory lying North of said line be erected into a new and distinct Township to be called and known by the name of Boston Township and that the place of holding elections in said township be at the house of Edwin Marsh and that Robert Hodges, George Russell (Upper) and George Russell (Lower) be appointed Judges of Election in said township.

County and Probate Court Minutes, Franklin Co, Arkansas
Monday 15 ? Jul 1838
Ordered that half of Range 29, the whole of Range 28 and two miles of the West part of Range 27 be a new township named Prairie and the election place shall be at William Barnards residence and the election judges shall be John Quesenberry, Masten P Pool and Sabert Scott.