Yes, Roger Jensen was the first storm chaser, in the modern sense of the word. He started chasing in 1953. David Hoadley started in 1956. Neil Ward began sometime in the late 1950s. It should be noted that all of these people did start taking storm photos at earlier dates.
Roger Jensen made it to the 1997 Stormtrack party at Bobby Prentice's house, and it always bothered me that he was kind of ignored there. I wonder if word simply didn't get out about who he was. He also came to the 1998 party at Tim Marshall's house, however I can't remember any details... if my memory is correct a group of younger chasers got to talking to him for a long time.
Tim