At the end of World War I, the United States Army—despite its recent experience with trenches, machine guns, barbed wire, airplanes, and even tanks—maintained a horse-mounted cavalry from a bygone era. From the end of World War I until well into World War II, senior leaders remained convinced that traditional cavalry units were useful in reconnaissance, and horses retained a leading role. Months into World War II, the true believers in the utility of the horses had their hopes shattered as the last horse cavalry units either dismounted to fight as infantry or traded their oat-eating horses for gasoline-guzzling iron ponies. The horse belonged to the past, and the armored truck was the way of the future.