Bankers and railroad magnates had more to gain from peace and war.
I did not say all businessmen: after all, there are some businesses that can always profit from warfare: munitions companies, equipment companies etc. Cannon manufacturers were quite happy.
But bankers prefer low risk and high returns.
There is no riskier situation than war for lenders. Not only does the rate of default on debt skyrocket in wartime, but the value of currency often declines as well.
Moreover, war interrupts commerce between the warring parties (bad for railroads and shipping), creates sabotage (bad for railroads) and usually involves government commandeering of resources at below-market prices (bad for railroads).
Recall that the Federal Gov required the losing states to repudiate all debts that were used to finance the CW. (Now off to IHOP)