151109-N-AT895-181 WASHINGTON (Nov. 9, 2015) Commandant of the Marine Corps (CMC) Gen. Robert Neller presents the first piece of cake to guest of honor, Assistant Secretary of the Navy for research, development and acquisition Sean J. Stackley during a cake cutting ceremony in honor of the U.S. Marine Corps 240th birthday at the Pentagon. (U.S. Navy photo by Mass Communication Specialist 1st Class Nathan Laird/Released)