A campaign cover is a broad-brimmed felt

Felt

Felt is a non-woven cloth that is produced by matting, condensing and pressing woollen fibres. While some types of felt are very soft, some are tough enough to form construction materials. Felt can be of any colour, and made into any shape or size....

 or straw hat, with a high crown, pinched symmetrically at the four corners (the "Montana crease").

It is associated with the New Zealand Army

New Zealand Army

The New Zealand Army , is the land component of the New Zealand Defence Force and comprises around 4,500 Regular Force personnel, 2,000 Territorial Force personnel and 500 civilians. Formerly the New Zealand Military Forces, the current name was adopted around 1946...

, the Royal Canadian Mounted Police

Royal Canadian Mounted Police

The Royal Canadian Mounted Police , literally ‘Royal Gendarmerie of Canada’; colloquially known as The Mounties, and internally as ‘The Force’) is the national police force of Canada, and one of the most recognized of its kind in the world. It is unique in the world as a national, federal,...

, the World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

 ground forces of the United States Army, contemporary U.S. military drill instructor

Drill instructor

A drill instructor is a non-commissioned officer or Staff Non-Commissioned Officer in the armed forces or police forces with specific duties that vary by country. In the U.S. armed forces, they are assigned the duty of indoctrinating new recruits entering the military into the customs and...

s, state police

State police (United States)

In the United States, state police are a police body unique to each U.S. state, having statewide authority to conduct law enforcement activities and criminal investigations...

 forces, park ranger

Park ranger

A park ranger or forest ranger is a person entrusted with protecting and preserving parklands – national, state, provincial, or local parks. Different countries use different names for the position. Ranger is the favored term in the United States, Canada, and the United Kingdom. Within the United...

s (and from them, their logo-cartoon and mascot Smokey Bear

Smokey Bear

Smokey Bear is a mascot of the United States Forest Service created to educate the public about the dangers of forest fires. An advertising campaign featuring Smokey was created in 1944 with the slogan, "Smokey Says – Care Will Prevent 9 out of 10 Forest Fires". Smokey Bear's later slogan,...

), Boy Scouts

Scouting

Scouting, also known as the Scout Movement, is a worldwide youth movement with the stated aim of supporting young people in their physical, mental and spiritual development, that they may play constructive roles in society....

, and others.

Although the campaign hat is occasionally referred to as a Stetson

Stetson

Stetsons are the brand of hat manufactured by the John B. Stetson Company of St. Joseph, Missouri.Stetson eventually became the world’s largest hat maker, producing over 3.3 million hats a year in a factory spread over . Today Stetson remains a family-owned concern...

, this is from its common manufacture in the late 19th century by that company.