The construction of the Overseas Highway and Railway Bridges was very important to the economic development of the Florida Keys. The bridges are significant surviving elements of Henry Flagler's Florida East Coast Railway intended to open the Florida coast for development. Begun in 1905 and completed in 1912, the bridges were intended to connect the Florida Keys to the mainland. The construction of Key Bridge began in 1906 and was completed in 1907; the 6.7 mile long Knight Key Bridge was constructed from 1909 to 1912; and the Old Bahia Honda Bridge (no longer in use), was also constructed from 1909 to 1912. The railroad extension was short-lived. In 1935 a severe hurricane hit the area and destroyed more than 30 miles of track. In the following years, the bridges were restored and converted from rail to vehicular traffic. The bridges helped open the area to tourism and today are part of U.S. Highway 1 connecting the Florida Keys to the mainland. Because of their remote location and the construction techniques employed, experts consider the bridges to be significant engineering achievements. - NPS