The series debuted in August 2012 to 1.11 million viewers, but dropped each subsequent week.
"Copper has been a fascinating and exciting experience for everyone involved," BBC America general manager Perry Simon told the trade. "The opportunity to work with Tom Fontana, Barry Levinson, Will Rokos, Thomas Kelly and the extraordinary cast and crew on this journey is one that we are extremely proud of. Their vision to retell the immigrant experience through the melting pot of New York City was an original and fresh idea that melded well with the essence of BBC America's programming. After 23 episodes, with Lincoln dead and the nation starting to heal, it seems a fitting moment to conclude this American story."
Copper, set in 1860s New York during the Civil War, will air its final episode this Sunday.