Answer:
preventing monopolization and/or conspiracy in the restraint of trade.
Explanation:
The Sherman Antitrust Act of 1890 was the first federal law that prohibited monopolistic practices. State legislatures had already passed some state laws that prohibited monopolies but since most monopolies engaged in interstate trade, they weren't affected by them, e.g. railroads, steel factories, etc.
This law was passed in order to address the issue from a national level and include monopolies that engaged in interstate trade.
