Apparently it's from 1901 (Murray code) or 1932 (ITA2).
The fact that both Apple's and CP/M codes came out roughly at the same time, both on microcomputers, shows that it was probably just a design decision.
rswail said ASCII, which definitely pre-dated Unix, not the other way around. And there was some to and fro about the equivalence of LineFeed and NewLine in the 1960s.