The gradual decline of the Roman Empire ushered in an era of European history called the Middle Ages, or the medieval period
Assuming you're referring to Theodore Roosevelt, one of the most successful things he did in terms of regulating big business was the "break up the trusts,"--in that he took to court companies that were suspected of colluding with other firms and forming monopolies.
Because there main product/export was cotton, so therefore it influenced them the most on the fact that they made more money.
hope this helps:)<span />
