Mezue ahịrịokwu na-esonụ: Carl sonyere na Company F nke 4th Wisconsin Infantry Regiment (National Guard) n'April 1896 ma wepụta onwe ya maka ọrụ na Spanish-American War na 1898. Brosius jere ozi na Company M nke 1st Wisconsin Infantry Regiment n'oge Agha ahụ, wee nwee nsọpụrụ na August 1900. N'ọnwa Julaị afọ 1913, ọ banyere ọzọ na ụlọ ọrụ D nke 1st Wisconsin Infantry Regiment; a kpọfere ya na ụlọ ọrụ F n'ọnwa Eprel afọ 1915 ma bulie ya n'ọkwa nke abụọ ka ọnwa abụọ gachara. A kpọbatara Brosius n'ọrụ maka
Agha ókèala Mexico na June 1916, ebe o duziri otu ndị agha na-agafe agafe. N'ịbụ onye nwetara ezigbo aha dị ka onye na-enye ọzụzụ ahụike, Brosius nọgidere na steeti n'oge Agha Iwa Mbụ, na-aga site n'ogige ruo n'ogige iji mejuputa mmemme ọzụzụ maka ndị agha America.