Statistics for occurrence #1 of “Little Missouri River” in chapter 13 of Frederick H. Dyer, Compendium of the War of the Rebellion: Regimental Histories:

...ecember 5-13. Princeton December 6. Expedition to Camden December 15. Steele's Expedition to Shreveport, La., March 23-May 3, 1864. Antoine and Wolf Creeks April 2. Elkins' Ferry, Little Missouri River , April 3-4. Prairie D'Anna April 9-12. White Oak Creek April 14. Camden Cross Roads April 15. Occupation of Camden April 16-18. Camden April 20. Marks Mills April 25. Moro...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
Little Missouri River (Wyoming, United States) 19 14 1 0 0 user votes
Little Missouri River (Arkansas, United States) 46 22 0 0 0 user votes
Little Missouri river (United States) 0 0 0 0 0 user votes

† This entity has been selected by the automated classifier as the most likely match in this context. It may or may not be the correct match.