The Florida Railroad was the first railroad to connect the east and west coasts of Florida, running from Fernandina to Cedar Key. The line later became part of the Seaboard Air Line Railroad, and, where still in use, is operated by CSX Transportation and the First Coast Railroad. The highway corridor of SR 24, US 301, and SR A1A closely parallels the former Florida Railroad.
The water route between the east coast and gulf coast of the United States passes through the Straits of Florida, close to the Florida Reef that lies just off the Florida Keys. Prior to the 20th century many ships were wrecked around the southern end of the Florida peninsula. A railroad across the northern end of the Florida peninsula would allow cargoes from ships in the Gulf of Mexico to be transferred to ships in the Atlantic Ocean, and vice versa, without the risk of passage through the Straits of Florida, while cutting 800 miles off the trip.
In 1842 the United States Congress commissioned a survey of a route for a railroad between the St. Mary's River and Cedar Key in the Territory of Florida. In 1853 the Florida Legislature chartered the Florida Railroad to build a 5 ft (1,524 mm)gauge rail line from Fernandina (near the mouth of the St. Mary's River) to Tampa, Florida, with a branch to Cedar Key. The president and chief stockholder of the Florida Railroad was U.S. Senator David Levy Yulee. Yulee decided to complete the line to Cedar Key first, leaving the connection to Tampa for later. Construction started in Fernandina in 1855. By 1858 the rail line was open between Fernandina and Starke, but the Panic of 1857 had left the railroad on the edge of bankruptcy. Yulee had to surrender a majority interest in the railroad to a northern investment syndicate headed by Edward Dickerson to save the company. The line was completed to Gainesville in 1859 and Cedar Key in 1861. Other towns served by the railroad included Callahan, Baldwin, Waldo and Archer. At 156 miles in length, it was the longest railroad to be completed in Florida before the start of the American Civil War.