Below is a list of railroads that were bought, leased, or in other ways had their track come under ownership or control by the Seaboard Air Line Railroad or one of its predecessors. The Seaboard Air Line Railroad merged with the Atlantic Coast Line Railroad on July 1, 1967, to form the Seaboard Coast Line Railroad.

Predecessor lines

The Seaboard main line from Richmond to Tampa, heart of its 2600-mile system in 1900, (today mostly CSX's "S" Line), had been built by the following companies:

Acquired lines

In the first decades of the 20th century, Seaboard expanded its holdings by acquiring the following lines, some of which were created by the Seaboard to construct new lines it wished to have. Acquired by purchase: Acquired by lease:

Seaboard Air Line Railway

American Agricultural and Chemical Company

Athens Terminal Company

Atlanta and Birmingham Air Line Railway

Atlantic, Suwannee River and Gulf Railway

Brooksville and Inverness Railway

Carolina, Atlantic and Western Railway

Carolina Central Railroad

Catawba Valley Railway

Central Railway of Georgia (Lyons Branch only)

Charlotte Harbor and Northern Railway

Charlotte, Monroe and Columbia Railroad

Chesterfield and Kershaw Railroad

Chesterfield and Lancaster Railroad

Columbus Railroad

Durham and Northern Railway

Florida Central and Peninsular Railroad

Florida, Peninsular and Gulf Railroad

Florida West Shore Railway

Gainesville Midland Railroad (bought by Seaboard in 1959)

Georgia and Alabama Railway

Georgia, Carolina and Northern Railway

Georgia, Florida and Alabama Railroad (gained control in 1928)

Kissimmee River Railway

Loganville and Lawrenceville Railroad

Macon, Dublin and Savannah Railroad

McRae Terminal Railway

Oxford and Coast Line Railroad

Line from Dickerson to Oxford, NC

Palmetto Railway

Plant City, Arcadia and Gulf Railway

Raleigh and Augusta Air Line Railroad

Raleigh and Charleston Railroad

Raleigh and Gaston Railroad

Richmond, Petersburg and Carolina Railroad

Roanoke and Tar River Railroad

Seaboard Air Line Belt Railroad

Seaboard-All Florida Railway

Seaboard and Roanoke Railroad

South Bound Railroad

Tallahassee, Perry and Southeastern Railway

Tampa Terminal Company

Tavares and Gulf Railroad (bought 1926)