These were privately printed for a local Army recruiting campaign in San Francisco and only a very limited number were ever printed. This was originally to be a recruiting poster for regular Army service, however, in the midst of printing these, the United States began a punitive expedition against Mexican revolutionaries along the U.S.-Mexico Border for which the poster became more synonymous. Often mistakenly labeled a WWI recruiting poster, this poster pre-dates the American entry into the war and thus should not be considered a true WWI recruiting poster.
The punitive expedition was fought against Poncho Villa following Villa's raid on Columbus, New Mexico, which killed a number of Americans.
Pictured is General Pershing, who would command Americans later in WWI Europe, spurring a rearing horse. The image is based on the painting "Napoleon at the St. Bernard Pass" by Jacques-Louis David.