In 1905, officials of the Agrico subsidiary Peace River Mining Company, along with engineers from the Army Corps of Engineers and 60 laborers, landed on Gasparilla Island, and surveying and construction of the railroad began. Probably the only buildings on the south end of the island at this time were the lighthouse and the assistant keeper's house. The railroad terminus with its pier would be built nearby. The Charlotte Harbor and Northern Railroad was completed in 1907. For the next 50 years phosphate was shipped out of the state-of-the-art port virtually without disruption. Phosphate-laden trains were off-loaded directly onto ocean-going freighters, and the ships took the valuable commodity to ports all over the world. In 1969 Port Boca Grande ranked as the fourth-busiest port in Florida.