Was the trademark in question previously registered by another company? If so, and it has since been abandoned, it is fair game.
However, if the other company is still using the trademark in commerce, even though they no longer hold a valid registration they still may have rights in their mark and could challenge your attempt to register the mark. It depends on what type of product is sold by the other company and which geographical area they are sold in. For example, if both you and the other company sell similar products in the Chicago area, the other company may have superior rights to the trademark, even if there is no Federal registration.
An Illinois-licensed trademark attorney can answer these preliminary questions for you, usually free of charge.