Henry Bacon, Sr. designed and supervised the construction of the coquina and granite seawall. The foundation of which was made by sinking a line of mattresses filled with logs, brush, shells and stones. Three floating derricks were used (one steam powered) were then used to place the heavy rocks on the mattresses. The rocks were then covered with coquina.
The New Inlet Dam was finished in 1881 and effectively closed off New Inlet from land out to Zeke's Island.
Eight years later Bacon completed the Swash Defense Dam from Zeke's Island to Smith's Island, a dam that was twice as long as "The Rocks." In the years since, shifting sand has formed a barrier line stretching the whole length from Fort Fisher all the way to Smith Island.