This unofficial motto of the US Marine Corps is an abbreviation for the Mandarin Gongye Hezhoushe, or industrial cooperative. The term was used in China, starting in 1938, to refer to small, industrial operations that were being established in rural China to replace the industrial centers that had been captured by the Japanese. The phrase was clipped to the initial characters of the two words, gung ho (or gung he, as it would be transliterated in Pinyin). This clipping became a slogan for the industrial cooperative movement.
Enter Lt. Col. Evans Carlson, US Marine Corps. Carlson was a military attaché in the US embassy to China in the late-30s. In China, Carlson reported on both the operations of the Chinese army in the field as well as the country’s industrial capacity and was favorably impressed by the industrial cooperatives. When the United States entered WWII, Carlson was appointed commander of the 2nd Marine Raider Battalion, a commando unit. Recalling his time in China, Carlson chose gung ho as the motto for his elite battalion and by late 1942 the term was widely adopted throughout the Marine Corps as an expression of spirit and “can do” attitude.
Carlson misunderstood the origin of the Chinese term, believing that it is an imperative gung (or kung, work) + ho (peace, harmony), or work together. This is not the origin, although the clipping of Gongye Hezhoushe to gung ho is clearly a deliberate one that takes advantage of this additional connotation. Many later sources repeated Carlson’s erroneous analysis of the origin.
From the 23 September 1942 issue of Yank magazine:
The Marine commandos have a new battle cry, “Gung Ho!” It’s Chinese for “Work Together.”
And from the 8 November 1942 New York Times Magazine:
Borrowing an idea from China, Carlson frequently has what he calls “kung-hou” meetings…Problems are threshed out and orders explained.1
Source: Dave Wilton, wordorigins.org
1Historical Dictionary of American Slang, v. 1, A-G, edited by Jonathan Lighter (New York: Random House, 1994), 993.