What was the total construction cost of the Panama Canal ?

The total construction cost of the Panama Canal was of approximately US$375,000,000, which included the US$10 million paid to Panama, and US$40 million paid to the French Canal Company for the rights to the Canal. Some authors mention a cost of US$387,000,000, but this amount includes the expense of fortifying the Canal, which is a cost separate from the actual Canal construction.