They brought supplies and troops to where they were needed. This previously would have taken a lot of horses to carry and at a slower pace.
it was the first war where widespread use of mechanized and electrified devices like railroad trains, aerial observation, telegraph, photography, torpedoes, mines, ironclad ships and rifles occurred.
The first trains were much slower than modern trains. For instance, in Britain, Robert Stephenson's Rocket, 1829, had a maximum speed of 28 mph (45 km/h).
It was the most modern war at the time.
The first modern horses in California were brought by the Spanish.The first cattle in California were brought by settlers on wagon trains from the US.
The Chinese civilisation was the first to have a civil service where joining it was open to anyone who could pass the entrance examination. As such it was the first modern civil service system.
Eisenhower
Both the American Civil War and World War One have been called the First Modern War.
The Civil War has become known as the first modern war for a variety of reasons. The first is that it was a truly modern "combined arms" war in which troops used cannons, cavalry, and small-arms fire, in addition to limited air forces. Secondly, it was a total war which affected large numbers of the civilian population. Thirdly, troops for both sides were mass-conscripted, resulting in the largest total number of soldiers gathered for war-making ever seen to that time in the modern age.
it used the first submarine in battle
Yes
The Spanish Civil War (1936-39)
Bullet trains were first invented in japan!