I'll make a guess and assume that the full sentence is something like this: 'Even back in the 1960s, there were very rudimentary internet systems used by academics in certain universities.' If that's the type of context, then 'Even back' doesn't have any significance as a unit of meaning. You have to look at the whole sentence. If you precede a phrase such as 'in the 1960s' with 'back', this indicates that this was a long time ago. And if you precede a phrase such as 'back in the 1960s' with 'Even', this indicates that this information is surprising or unexpected.

Even a short context is always needed. Looking at it as it is now, I could say "It was a somebody's smooth back", i.e. not humpy and lumpy. But I think it will not make any sense in your case.

This question needs context to answer fully. What was the entire sentence?