The U.S. Navy and Coast Guard officer rank of Lieutenant (Junior Grade) is equivalent to a First Lieutenant in the other three branches of the Armed Forces of the United States, but only one of them—the Marine Corps—uses precisely the same design and dimensions as the Navy and Coast Guard for its metal rank insignia typically worn on outerwear garments. Besides sharing rank insignia, First Lieutenants and Lieutenants (Junior Grade) are in the same (O-2) pay grade.
In the Navy, the rank of Lieutenant (Junior Grade) was not established until 1883, when it replaced the title “Master in line for Promotion” for U.S. Naval Academy Graduates. Early in its history, the Marine Corps had two Lieutenants per Navy vessel, one higher in rank than the other but sharing the same designation as simply Lieutenant: rank insignia, not designation, was the only way to determine which was the Senior Officer. This was corrected in 1798 with the passage of the Act of 11 July 1798, which established the Department of the Navy and organized the Marines into a Corps with four officer ranks: Major, Captain, First and Second Lieutenant.
More Coast Guard Ensign Rank Insignia / Devices
Collar Rank Insignia
Sleeve Lacing
O-1 Tie Tack/Clasp
More Devices / Accouterments for Coast Guard Ensigns
Junior Officer Combination Cap
Officer Cap Device
Line Officer Sleeve Device
Officer Belt Buckle
Officer Cuff Links
Officer Tie Tack/Clasp