Complex sentence: William C. C. Claiborne was sent to take possession of the territory, entering the capital of St. Francisville with his forces on December 6,1810, and Baton Rouge on December 10,1810.
Split into simpler sentences: William C. C. Claiborne was sent to take possession of the territory. Claiborne entered St. Francisville with his forces on December 6,1810, and Baton Rouge on December 10,1810.