Born in April 1852 in Providence, Rhode Island, Gillick joined the Navy from that state on July 16, 1881, at the age of 29 years and 3 months.
On that day, while Lancaster was at Marseille, France, a boy fell into the water from a breakwater near the ship.
Gillick and another sailor, Ordinary Seaman Apprentice John F. Auer, jumped overboard and rescued him.
For this action, both Gillick and Auer were awarded the Medal of Honor a year later, on October 18, 1884.
Jumping overboard from the Lancaster, Gillick rescued from drowning a French lad who had fallen into the sea from a stone pier astern of the ship.