[wideawake]

Not, it would have caused a major supply interruption. It would have dragged the war on for years IMO.

When there are fat, guaranteed government contracts to be had, manufacturers move very quickly.

A year, certainly. Multiple years? I'm not sold on that one.

[Old Teufel Hunden]

"When there are fat, guaranteed government contracts to be had, manufacturers move very quickly."

Cannon's were made of iron back then. There's a reason that Pittsburgh became the iron and steel capital. It has a unique set of qualities (coal, water, natural resources) that made it this way. In 1863, it would have taken years to re-build the foundries and mills necessary to make these cannons. No matter what guaranteed big fat contracts said. That was a simplistic answer born of lack of understanding.