From Florida - A Guide to the Southernmost State - Part II. Principal Cities - Jacksonville:
Railroad Station: Union Terminal, 1000 W. Bay St., for Atlantic Coast Line R.R., Seaboard Air Line Ry., Southern Ry., Florida East Coast Ry., and Georgia-Southern and Florida R.R.
Today, the Terminal looks very similar as it did back in the 1930s (see black & white above photo). The major difference is that the front parking lot is no longer present. Parking lots are now located on the left and rear sides of the Terminal.
Additional information about Union Terminal is available from Wikipedia: "The first Union Station in Jacksonville was built by the Savannah, Florida and Western Railway (later part of the Atlantic Coast Line Railroad) in 1883. The Jacksonville, Tampa and Key West Railway (also later part of the ACL) began to use it in 1884. Other terminals served the Florida Central and Peninsular Railroad (later part of the Seaboard Air Line Railway), the Florida East Coast Railway, and the Georgia Southern and Florida Railway."
"The company was incorporated in 1894 by Henry Flagler, who owned the Florida East Coast Railway. Its first Union Depot opened on February 4, 1895, and was completed on January 15, 1897. It came to be known as the Flagler Depot."
"The second Union Station (pictured in this waymark) opened in 1919 on the site of the original one, and was last used on January 3, 1974 (Amtrak now stops several miles north). In 1982, a public-private partnership was started, led by former CSX chairman Prime F. Osborn III. The new convention center opened at the site on October 17, 1986."