Its mission is to train Cadets in basic military leadership and commission them as 2nd Lieutenants upon the completion of a bachelor's degree.

[1] Prior to the American Civil War, the small number of officers the Army needed was provided by the United States Military Academy at West Point, New York and a few other colleges, such as Norwich University.

With the expansion of the Army to unprecedented size for the Civil War, the need for trained officers quickly exceeded the number available.

The first students were described as "being fine of muscle and brain but had to be taught to read and do simple arithmetic,"[3] perhaps explaining why military training did not begin immediately.

[6] Education in military tactics continued until 1877 when all guns were taken for the Nez Perce Wars, so "drill was not among the college activities of the time.

The new band, together with two companies of Cadets, marched down the railroad station to perform when President William Henry Harrison arrived on the Presidential train.

Lieutenant Woodbridge Geary, US Army, who'd been Professor of Military Science for two years, was killed in the Philippine Islands.

Later that year, Major Edwards of the Oregon National Guard, arrived fresh from the Spanish–American War to head the military program.

City merchants brought out crates of oranges for the Cadets and visitors came to the camp, "an enjoyment long to be remembered.

By this time there were four companies of infantry, with detachments of field artillery, Cavalry, Engineers, Signal, and Hospital Corps and a 28-piece band.

The blue uniform changed to olive drab, handsome with a black visored cap, white gloves and puttees.

[8] Two historic leaders were at OAC during this period: College President William Jasper Kerr, who was far seeing in his objectives and believed in the distribution of responsibility; and Captain Ulysses G. McAlexander, whose record as a commandant and soldier was outstanding.

Captain H. L. Beard, long their conductor, took the band to the 1915 Panama–Pacific International Exposition in San Francisco, California, where they played for a month, bringing much acclaim to Oregon State.

[2] With the increasing size and popularity of the Cadet regiment, the Oregon Legislative Assembly passed an act providing for the construction of the present armory.

In this accelerated program there were over 3,000 students carrying 14 hours of collegiate work weekly (principally in engineering) besides their military subjects.

Providing officer training for both the US Navy and the US Marine Corps, it is now one of the largest in the nation and has earned the unofficial title "Naval Academy of the Northwest.

The Air Force ROTC draws more freshmen scholarships than any other AFROTC unit in the nation and has had over 1,000 officers commissioned, including the first women in 1970.

The Army ROTC, from its beginning in 1917, had commissioned enough officers to make Oregon State the leader in the nation among non-military schools.