The first issue of the series prominently displays "Volume Two" on the cover and the indicia noted the same for the first couple years. No "Volume One" was ever actually published, but was intended (or perhaps just teased) to be a series chronicling the adventures of Supreme before he left Earth 50 years earlier.
#1-42 & #63-68 published by Image. #43-47 by Maximum Press as "Supreme: The New Adventures." #48-56 by Awesome.
The series originally ended in 1998 with #56 and was restarted in 2012 with #63.
To get to #63, Liefeld is using the following series in the count:
56 issues - Supreme
6 issues - Supreme: The Return