Q1
They invented the double barreled cannon. Made in 1862, Athens, Georgia, and costed $350.13 and a length of 4ft 8 in. Both barrels would fire at the same Tim causing double the damage

Q2
They create railroads which was the first mass transport of land forces. They also built the first naval aircraft carrier, and the widespread, effective use of rifles in battle.

Q3
They used submarines and machine guns, aircraft carriers which we still used today, but just a bit more advanced

Science and Technology