I don't know why the 1855 Census was taken. I have a paperback 1855 Census of the Choctaw Nation by Alma Mason I bought many years ago. In Pushmataha District Atoka County #2 is R. L. Cochran with Jincy, Martha, Isabel, Delilah, Emily, Bailey but there is also a listing in Choctaws Living in Chickasaw Nation 1855 #141 R.S. Cochran(might be a misprint since it was hard to read those microfilms probably) ---, Martha, Libby, D---, Emily, Baby. #144 in Chickasaw Nation is Joseph Colbert and family, 145 is Henry Colbert and #158 is Winchester Colbert with Easter, H---, Paka, Billy, Noah, Vina. Jincy Bohanan Cochran's mother is listed in Apukshunnubbe District Wade County Betsey(Anderson)Bohanon with her(Jincy) brothers and sisters Lina, Judah(Judith), Washington, Ellis, Joslin Jones. also 1/2 brothers Samuel And Thompson Bohanan listed with their mother Phoebe(Anderson) Bohanon Hampton. Jincy's parents were Betsey Anderson who married William Bohanan Jr. Phoebe Anderson who was Betsey's sister also was married to William Bohanan Jr. then married a Hampton. William Bohanan Sr. and Choctaw Full Blood was the father of William Bohanon Jr. They were the mixed blood Choctaw Bohanan Family. Betsey and Phoebe descend from Daniel Anderson and Michou Jenny Battiest. Jincy was born in Mississippi. Tons of families married into the Bohanan family--Andersons, Springs, Mccurtains, Gardners, Hudsons, Kings, Dukes,Hamptons etc.. My Gr.gr.gr. grandfather Ellis Bohanon was a brother of Jinny or Jincy or Jane Cochran. He also was 1/2 Choctaw. He named his daughter Jincy.
I also found from the Library of Congress Historical Collection, American Memory #32 which is online The Constitution of Laws of the Choctaw Nation:A Century of Lawmaking for a New Nation: US Congressional Documents and debates 1774-1873
Constitution of The Choctaw Nation
An act providing pay of Mr. Cochran that the sum of 16 dollars be set an appropriated to be paid to R. L. Cochran for the rent of a cabin for the senate to do business in. Approved Oct. 9, 1845
A resolution authorizing the clerks to have a fence made around the council house. That the clerks are hearby authorized and instructed to make a bargain with Mr. Cochran, or any other person, to put up a ten rail fence and staked and ridered, of one acre of ground around the General Council House, also to shrub and trim the saplings and put up the gate: the same will not cost more that 30 dollars to be paid out of the National Funds of 1845. Appropriated Oct. 1844.
An Act making appropriation for the pay of Mr. Cochran that the sum of 8 dollars be appropriated to pay Mr. Cochran for the use of his house 2 years as Senate chamber, out of the district funds of several districts.
Theres a map in the 1855 Census book with a Boggy Depot over by Clear Boggy River in Pushmataha district and a Muddy Boggy River is listed in Pushmataha district