Complex sentence: Following the killings carried out by the Kiowa, Capt. Gaines Lawson company (25th Infantry), sent to garrison Anadarko, was reached by Colonel John W. "Black Jack" Davidson with four companies of 10th Cavalry from Fort Sill.
Split into simpler sentences: Following the killings carried out by the Kiowa, Capt. Gaines Lawson and his company (25th Infantry) were sent to garrison Anadarko. They were reached by Colonel John W. "Black Jack" Davidson with four companies of 10th Cavalry from Fort Sill.