After running though central Bartow, it continued south through Fort Meade, Bowling Green, Wauchula, and Zolfo Springs.

[1] The Fort Myers Southern Branch extended as far south as Marco Island at its greatest extent.

Surveying work to determine the route for the Charlotte Harbor Division was accomplished by Punta Gorda civil engineer Albert W. Gilchrist, who would later serve as Florida's 20th governor.

The Florida Southern's Charlotte Harbor Division was completed with its first train to its terminus in Punta Gorda (initially known as Trabue) on July 24, 1886.

[5] Fort Myers was seeking railroad service at the time and had already been established as a city unlike Punta Gorda.

Construction commenced promptly on an extension to Fort Myers via Tice, which made it the ACL's first expansion of the former Plant System.

The alignment through Tice was selected so the line would cross the wide Caloosahatchee River farther upstream at Beautiful Island, where a series of shorter trestles could be built.

[2] The northernmost trestle originally had a steel swing span built by the American Bridge Company to accommodate river traffic.

Fort Myers would remain the southernmost point of the entire Atlantic Coast Line Railroad system until the Florida land boom of the 1920s.

[2] By the end of 1927, the Atlantic Coast Line was running regular passenger train service to Naples.

By 1944, the Atlantic Coast Line abandoned the Fort Myers Southern Branch from Marco Island to a point near Vanderbilt Beach.

[14] However, intercity passenger service on the line was discontinued in 1971 upon the creation of Amtrak, who opted not to serve Southwest Florida.

The area around the line's new terminus in North Naples was subsequently developed into the Rail Head Industrial Park.

[16] In 1980, the Seaboard Coast Line's parent company merged with the Chessie System, creating the CSX Corporation.

[18] This segment of the line still carries large amounts of phosphate from The Mosaic Company's South Fort Meade mine.

However, the southernmost 15 miles of the Seminole Gulf Railway from Alico Road (near San Carlos Park) to North Naples is inactive and has not had any active shippers since around 2008.

[21] Seminole Gulf rebuilt most of the ACL-era trestles over the Caloosahatchee River in early 2024 after they were destroyed by Hurricane Ian in 2022.

Collier Boulevard (SR 951) runs along the original alignment of the line from its intersection with the Tamiami Trail to Marco Island.