The Missouri State Highway Patrol was created in 1931 by an act of the 56th Missouri General Assembly, during the tenure of Governor Henry S. Caulfield.
Although this new Highway Patrol's authorized strength was set at 125 uniformed officers, due to limited appropriations, the Patrol began with 55 officers and a handful of civilians. By the 2000s the Missouri State Highway Patrol has grown to include more than 1,400 uniformed civilians and support staff, and 1,100 uniformed members.
Since its inception in 1931, the Missouri State Highway Patrol has evolved from simply a highway patrolling force to a full-service, accredited law enforcement agency. While enforcing traffic laws and promoting safety on Missouri's approximately 33,000 miles of state-maintained highways remains the Patrol's primary responsibility, the Patrol has been tasked by the Governor and the legislature with many additional law enforcement duties including: motor vehicle inspection, commercial vehicle enforcement, driver's license examinations, criminal investigations, criminal laboratory analysis and research, public education, gaming enforcement, law enforcement training, and more.
In 1992 the Missouri State Highway Patrol became only the 10th State Police/Highway Patrol to receive accreditation from the Commission on Accreditation for Law Enforcement Agencies.
This accreditation demonstrates the Patrol's commitment to professionalism and acceptance of high standards of excellence in law enforcement. This process also provides an ongoing evaluation of the Patrol's policies and procedures so that it may continue to grow and improve in the future.