The original merchant marine insignia was prescribed in "Changes in Uniform Regulations, United States Navy, 1913 No.
Uniforms for the entire Naval Reserve were authorized by Congress on 31 March 1915 as the possibility of U.S. involvement in World War I increased.
In April 1938, at a conference chaired by Captain Chester W. Nimitz, U.S. Navy, Assistant Chief of the Bureau of Navigation, the new insignia was presented to the four heads of the state maritime school ships.
The shield has 13 stars and stripes with crossed anchors and was taken from the U.S. Navy officer's cap device which was first authorized in 1869.
[7][8] Beginning in 1942 the Secretary of the Navy authorized all US naval reserve midshipmen who were enrolled at the United States Merchant Marine Academy (USMMA) to wear the USNR/MMR warfare pin.
However, this rule was rescinded in 2011 when the final qualification for designation as a Navy Strategic Sealift Officer was changed.
Presently, all US Navy Reserve Midshipmen at the United States Merchant Marine Academy wear the modified device of the former USNR/MMR insignia that no longer has the "USNR" letters on it.