Second Award: Served as boatswain's mate on board the U.S.S. Don, 1 May 1865. Engaged in picking up the crew of Picket Launch No. 6, which had swamped. Mullen, seeing an officer who at that time was no longer able to keep up and was below the surface of the water, jumped overboard and brought the officer to the boat, thereby rescuing him from drowning, which brave action entitled him to wear a bar on the medal he had already received at Mattox Creek, 17 March 1865.