 Complete the following phrase:  On 12 January 1887, Cronin was commissioned as a Second Lieutet of the Infantry and served on the United States frontier from 18871893. After his frontier duty, Cronin became an instructor at West Point from 18931897. With the outbreak of the SpanishAmerican War, Cronin became Regimental Adjutant of the 25th Infantry and served in the 