What a great reply!
I even think the Erie Canal ‘decided’ the Civil War.
It tied the Northwest Territories, though they were settled to a great extent by Southerners, to the Northeast.
Slaveholding capitalists had no reason to invest in such transportation projects to the west.
Slavery was a failure in very many ways.
It wasn't just the canal, although that was a vital link in the chain. There were tons of roads and railroads built pre-Civil War that resulted in tying the regions together for their mutual interests.
Best book I've read for giving me an understanding of how economic interests played a role in ALL of the country's history was Westward Expansion by Ray Allen Billington.