Ensign comes from the Latin word insignia that meant and still means emblem or banner. A warrior who carried his lord's banner or ensign became known as an ensign bearer and then just an Ensign. Later, the Ensign, still bearing his banner, led a military unit of about 500 foot soldiers called an "ensigne." As a military rank Ensign started in the French army as a junior officer and soon entered the French navy whose lowest commissioned rank is still Enseigne. Ensigns served in our Revolutionary War in infantry regiments where they were the lowest ranking commissioned officers. After the war they also served in Regular Army infantry regiments from 1796 to 1814.
Ensigns did not join our Navy until 1862 to fill the need for a rank for graduates of the Naval Academy who had been called Passed Midshipmen, and to have an equivalent rank to the Army Second Lieutenant. Also, in 1862, Ensigns wore a sleeve stripe of one one-quarter-inch wide gold lace, which increased to the present one-half-inch wide lace in 1881. The Ensign got his single gold bar rank insignia in 1922.
From: Why is the Colonel Called "Kernal"? The Origin of the Ranks and Rank Insignia Now Used by the United States Armed Forces
Information borrowed Naval Historical Center
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