The Seaboard Coast Line emerged on July 1, 1967, following the merger of the Seaboard Air Line Railroad with the Atlantic Coast Line Railroad. The combined system totaled , the eighth largest in the United States at the time. The railroad had $1.2 billion in assets and revenue with a 54% market share of rail service in the Southeast, facing competition primarily from the Southern. The seemingly redundant name resulted from the longstanding short-form names of these two major Southeastern railroads. For years, SAL had been popularly known as "Seaboard," while ACL was known as "the Coast Line."