The Antonio López was a historic vessel of the Spanish merchant marine. When built in 1881–82, she was the first Spanish-built steel merchant vessel with a complete electrical lighting system. She was also one of the most important Spanish blockade-runners during the American blockade of (then-Spanish) Puerto Rico during the Spanish–American War, its crew delivering a supply of military materials critical to the island's defense after the ship was grounded in June 1898 under fire from the Americans. The shipwreck is the only known Spanish wreck in American waters from the conflict. Its wreck site, in 1,700 feet (520 m) of water off Dorado, Puerto Rico, was designated a National Historic Landmark in 1997.