While it is not a currently recognized chicken breed, the fame of the Blue Hen can be traced back to the American Revolution: Col. John Haslet's 1st Delaware Regiment (later the 198th Signal Battalion), which reported for duty near the outset of the war, in January 1776, were nicknamed "the Blue Hen's Chickens", though more commonly known as "the Fighting Delawares". Within the regiment, the second company was composed of men from Kent County and was under the command of Capt. John Caldwell, who was an avid fan and owner of gamecocks. The troops often amused themselves by staging cock fights with a variety known as the Kent County blue hen, recognizable for its blue plumage. The renown of these chickens spread rapidly during the time when cock fighting was a popular form of amusement, and the "Blue Hen's Chickens" developed quite a reputation for ferocity and fighting success. Caldwell's company likewise acquired a considerable reputation for its own fighting prowess. In August 1780, the surviving Delaware units were joined with the Maryland regiment in a brigade, and Captain Robert Kirkwood, the senior remaining Delaware officer, was in charge of Delaware's then-battalion, and he acquired the nickname "Blue Hen" as well.
In 1939, the Delaware General Assembly named the Blue Hen Chicken the official state bird. It is one of only three US state birds that is not a species native to the United States.
The University of Delaware's College of Agriculture & Natural Resources maintains a breeding group of the Blue Hen Chicken on the campus farm.