I post to add a bit of early US Army canteen ref. to the site. Joseph Koenig (1858-1929) is a key individual re these canteens c. 1910s. In 1893, penniless, he got his start with aluminum and by 1908 the "inventive genius" emerged as a founding father of aluminum manufacturing in the midwest US. 1908/09 Joseph and 2 other companies merged to form The Aluminum Goods Manufacturing Co. of Manitowoc. He was VP (age 52) and it is his company that later offers our famous MIRRO brand. 1908/09 Joseph completes invention of his new and improved soldier's seamless aluminum canteen. 1909 The new canteen is in production and 500 1st run examples went to the US Infantry for trials. 1910 US infantry adopts his canteen. 1911 Joseph applies for patent (seen next) for his canteen and his processes, patent granted in 1913. Of note A. The patent is granted to the individual Joseph Koenig of Two Rivers (no Manitowoc / company name). B. often referred to as US "WW1" or "c. WW1" canteens and that's fine but fwiw his 1st run was produced in 1909... nearly a decade before our doughboys joined the fight.