After examination of troop strengths, it appears that the largest "military operation" in Indian Territory during the Civil War occurred on November 6, 1864, during Price's Retreat in IT. What a surprise!!

Here, I define a military operation (not a battle) as a coordinated act of opposing military forces to engage in battle on that day. Federal cavalry forces of MG S. R. Curtis' Army of the Border and those of BG J. M. Thayer were attempting to find and destroy those of Confederate MG Sterling Price's Army of Missouri. All three forces on November 6, 1864 were in the field and marching north of the Arkansas River nearby in the Cherokee Nation of Indian Territory, and all were within "striking distance" of one another. Official Records suggest that the Federal forces of Curtis were about 3,500 cavalry (41-1-516), those of Thayer were estimated to be 3,000 troopers (41-4-505), and those of Price were estimated to be about 10,000 men (41-4-516). The resulting peak troop movement of 16,500 men in Indian Territory occurred about 3:00 p.m. on 11-6-1864. Comparative statistics for Honey Springs: [Blunt (3,000), Cooper (5,700) and Cabell (3,000) = 11,700 on 7-17-1863], and for North Fork Town (to Perryville): [Blunt (4,500), Cooper (5,700) and Cabell (3,000) = 13,200 on 8-26-1863].

The largest military operation in Indian Territory during the Civil War should be recognized...