Why didn’t the US government declare monopolies to be illegal?

In response to a large public outcry to check the price-fixing abuses of these monopolies, the Sherman Antitrust Act was passed in 1890. This act banned trusts and monopolistic combinations that lessened or otherwise hampered interstate and international trade.

the conditions that made the byzantine empire vulnerable to attacks by the muslin turks were the sack of constantinople by western crusaders, the conquests of the sultanate of rum, presence of rival kingdoms and finally the set up of fiefdoms at the empire which were owned by the ghazis (turkish warriors).