The Union States lacked the resources that were available in the south, but had most of the manufacturing ability.
After the war was lost, the South, which had been fairly wealthy had two huge problems. Much of their former wealth was in the value of the slaves held by the wealthy, but that wealth vanished with the passage of the 13th Amendment.
But it was a provision of the 14th Amendment that doomed the South economically. All debts, including currency issued by the CSA or any other the seceding states was null and void. Only US currency, gold and silver could pay debts, including real estate taxes. Carpetbaggers with lots of cash could buy up property for next to nothing since patriotic southerners had exchanged their gold and silver for Confederate bonds and banknotes.
Wild game and knowledge to harvest it and the capability to fire accurately