The American Civil War did more forever changed the landscape of the United States. It altered state lines, reshaped political parties, led to mass migration, and forged the modern age of firearms.
The United States military has a long history of struggling with weapon procurement. The adopted weapon platforms of the United States usually fall within two categories. One, they are poor choices with serious flaws. Two, they are implemented well ahead of when they are ready. The Springfield Armory Model 1898 rifle falls into the former category.