Final answer:
North Dakota issued the first legal license to practice chiropractic in the year 1915, establishing state recognition and regulation for the profession.
Step-by-step explanation:
The year that North Dakota issued the first legal license to practice chiropractic was 1915. Chiropractic is a form of alternative medicine that focuses on diagnosis and treatment of mechanical disorders of the musculoskeletal system, especially the spine. North Dakota was among the early states to recognize and regulate the practice of chiropractic, granting legal licenses to chiropractors to ensure that practitioners met certain standards of training and professionalism.