The DVD mentioned above may be for the 1973 film version rather than the later TV series.
I certainly remember watching the first season, produced by CBS, back in the late 70s. For some reason it was cancelled after the first year even though it was both well written and well acted and I could not agree more strongly with your opinion of John Houseman.
I cannot comment on the final three seasons, produced by Showtime in the mid 80s, as I never had the opportunity to watch them and so never saw Hart graduate Harvard Law School.
http://uk.imdb.com/title/tt0077058/ To quote Professor Charles W. Kingsfield, Jr.
"You teach yourselves the law. I train your minds. You come in here with a skull full of mush, and if you survive, you'll leave thinking like a lawyer."