Like the other stations on the Congress Line (and the future Dan Ryan Line and O'Hare Line on the Kennedy Expressway) the station has a single island platform. When the station originally opened, its name was just "Halsted" like its predecessor.
This station, like others along the Congress Line (which would later become parts of the Dan Ryan and O'Hare lines), has a single island platform.  It was initially named simply "Halsted," similar to its predecessor.