Philip Justice owned a factory for cast steel springs and other railroad parts and equipment in North Philadelphia. He was the first American to import steel tires for railroad cars, which he sold to Philadelphia's Baldwin Locomotive works. During the Civil War, he invented "an improved mode of attaching Armor Plates to Vessels" and he turned over much of his plant to military production, but he seems to have been far more interested in profit than patriotism: an investigation and court case found that, in the words of the US Supreme Court, "the arms were unserviceable and unsafe for troops to handle."