Soon thereafter, the 21st Infantry was shipped to the Philippines to reinforce the American Army dealing with the growing Philippine Insurrection. There, Conley took part in many operations around Manila and outlying districts, earning commendation from the senior leaders for his skill in the field. Captain Conley remained with the 21st Infantry as it returned to the United States, before serving at Fort Niagara, and back in the Philippines. For a period of time, Captain Conley was assigned as the Professor of Military Science and Tactics (PMS&amp;T) at the Maryland Agriculture College (today part of the University of Maryland).