The flag of North Dakota represents the U.S. state of North Dakota. Adopted on March 11, 1911, its design is an almost exact copy of the unit banner carried by the state's troop contingent in the Philippine–American War. The flag's official proportions are 33:26, significantly shorter than many other state flags; however, in practice, the flag is produced and sold in 5:3 ratios. The state code specifies that the flag must be made of blue silk or some other material that is capable of '[withstanding] the elements'. (Source: Wikipedia.org, CC BY-SA)