El Pozo is one of five drawings produced by William Glackens used to illustrate an eyewitness account as reported in the October 1898 issue of McClure's Magazine of the assault on San Juan Hill, overlooking Santiago, Cuba. Glackens was the only artist sent by the magazine to cover the Spanish American War fought in the spring and summer of 1898. His sketches in the field capture the atmosphere and mood of this short-lived war. After the war, Glackens concentrated on his art, gaining renown as a member of what came to be known as the "Ashcan School" of American painters.