What Is the Longest Ad Campaign in US History?

Smokey Bear is America’s longest running ad campaign. Created in 1944 in response to an increase in wildfires, Smokey Bear ads were used to prevent wildfires. The development of Smokey Bear came during World War II, as many men, including firefighters, were enlisted, and the general public was urged to be more diligent in order to prevent more wildfires. The Forest Service along with the Wartime Advertising Council and Association of State Foresters used posters and slogans to suggest people can prevent fires and win the war.

More about Smokey Bear:

Prior to Smokey Bear, Disney allowed the use of a Bambi poster for forest fire prevention.
Artist Albert Staehle (1899-1974) created the first Smokey Bear poster, which depicts the bear pouring water on an open campfire.
In 1950, an American black bear was rescued during a wildfire in New Mexico, which burned 17,000 acres (69 km). The bear was named Hotfoot Teddy, but later changed to Smokey after the mascot.