 Having received his commission, Jackson served as assistant inspector of ordnance and then inspector of ordnance at the Midvale Steel Works, then drew sea duty aboard the torpedo boat "Cushing" and monitor "Puritan".In 1897, he married the daughter of Rear Admiral William T. Sampson, who would achieve fame a year later at the Battle of Santiago Bay.He won the annual essay contest administered by the United States Naval Institute in 1900.