Battery Gregg was named for Captain John C. Gregg, who served as a captain in the 4th Infantry and was killed in action near Mariquana, Philippine Islands, on March 31, 1899. Completed in December 1900 as the fourth of Fort Mott’s five batteries to be constructed, it had emplacements for two 5-inch rapid fire guns, model 1900, mounted on pedestal mounts with shields, although both guns were not installed there until 1906. Test firing in 1907 shattered windows on the post and neighboring farms. Produced at the Watervliet Arsenal, N.Y., the guns were designed for all-around 360-degree fire capability, but fort personnel reported that newly planted trees on the reservation obstructed the field of view when the guns were installed. In 1913, the guns were removed and later shipped to Benica Arsenal, California. By 1920, after the guns had been removed for several years, a Battery Commander’s Station had been built on emplacement No. 1 to direct the fire of the 10-inch guns of Battery Harker; from there, the battery commander supervised the operation of his guns, checked the work of the plotting room by setting his sighting instrument where the target should be and judging the accuracy of the plot, and spotted the fall of the shot to make corrections needed to bring the battery’s fire on target.