Construction on the entire causeway and the three original bridges lasted 15 months and cost $2.73 million. It was the last major project designed by Hector F.J. Estrup, Civil Engineer, owner of Caribbean Engineers. The Sanibel Causeway was completed and opened for traffic on May 26, 1963. Due to the causeway, Sanibel Island experienced major growth in the early 1970s leading to Sanibel's incorporation into Lee County's third city, which took place on November 5, 1974. Former congressman and CIA director Porter Goss served as Sanibel's first mayor.