As the story of C’s birth goes hand in hand with the creation of Unix, the first C compiler can be traced back to the early 1970’s. I've detailed the history of C in my previous article Tracing the Lines: From the Telephone to Unix, which includes a brief summary of this history.
Great article. I remember lattice C on the Amiga platform
The PDP-10 was a completely different architecture from the PDP-11 (e.g. it had 36-bit words). It never ran Unix.