There seems to be a bit of confusing of "new technology" with "new inventions". Most new devices need development, which requires time, labor, and money. Even though the Confederacy attempted to use some new things- notably the submarine, floating mines- there was limited possible development of them and they never became important... it's hard to imagine they had much effect (even though Steam Punks everywhere would no doubt love the idea of the steam-powered cannon actually getting used).