Protecting your trademark basically consists of preventing others from using your mark in a context where it might confuse consumers, and recovering money from someone who uses your mark knowing it was protected.
The laws favor businesses who first used the mark, and much of copyright law comes from the Lanham Act. The Lanham Act was designed to prevent trademark infringement. The law broadly prohibits uses of trademarks, trade names, and trade dress that are likely to cause confusion about the source of a product or service. Infringement law protects consumers from being misled by the use of infringing marks and also protects producers from unfair practices by an imitating competitor.