The 1st Infantry Division (“The Big Red One”) of the United States Army is the oldest continuously serving division in the Regular Army. It has been in continuous service since 1917, when it was founded during World War I. After its shoulder patch, it was dubbed "The Big Red One" (abbreviated "BRO"), and it is also known as "The Fighting First." The division has also been given troop names like "The Big Dead One" and "The Bloody First," which are puns on its official designations. Its current headquarters are in Fort Riley, Kansas.
There is no credible source that explains how the 1st Infantry Division's emblem came to be during World War I. There are two theories as to how the idea of the patch came about. According to the first theory, the 1st Division supply trucks were made in England. The drivers would paint a large "1" on the side of each vehicle to ensure that the 1st Division's trucks were not to be confused with those of other allies. The division engineers would later go one step farther and wear a crimson number one on their sleeves.
According to a second idea, a division general decided that the unit needed a shoulder insignia. He decided to make a "1" out of red flannel underwear. "The general's underwear is showing!" one lieutenant exclaimed as he displayed his prototype to his men. The commander was offended and challenged the young lieutenant to come up with a better idea. As a result, the young officer took a piece of gray material from a captive soldier's uniform and sewed the red "1" on top.
The Regular Army's First Expeditionary Division, later known as the 1st Infantry Division, was formed on May 24th, 1917, and was organized on June 8th, 1917, at Fort Jay, on Governors Island in New York harbor, under the command of Brigadier General William L. Sibert, from Army units then serving on the United States-Mexico border and at various Army posts across the country.
Rags, a mixed breed terrier, was the division's canine mascot. Rags became the division's mascot in 1918 and remained so until his death in 1936. Rags rose to fame as a fighting dog after carrying a vital message while being bombed and gassed during the key Argonne Campaign, saving many lives.