Pre-WWI US Army Officer’s Campaign Hat from the Mexican Expedition, featuring a horse hair braid. This hat is attributed to 2nd LT Arthur P. Amundson. His headstone application (a copy of which is included) states that Amundson served from February 15, 1913, to February 14, 1916, with Co I, 3rd Inf, Minnesota. He then enlisted in the Minnesota National Guard on March 12, 1916, and was mobilized for border service in June of that year. Throughout the Mexican Border Campaign, the entire Minnesota National Guard was activated for border service, though they did not engage in combat. After demobilization, Amundson continued his Federal service until 1917, accepting a commission in field artillery on October 8, 1918. The horse hair braid on the hat is a symbol of border service and, while it can be found on some hats from that era, it remains a rare feature. The hat has some wear and tear: light mothing, an incomplete leather sweatband, a broken but present chinstrap, some breakage in the horse hair band, and a missing ribbon that would typically be situated behind the horse hair band. Despite these condition issues, both the cap and its braid are rare finds.