Meaning (and History?) of “back of”?

Question

I've come across the term "back of" (meaning "behind" in a physical or metaphorical sense) in a number of different works from around the turn of the 20th century*. Was this a linguistic fad of some sort that (thankfully) died out somewhere in the Twenties? When used, it seems to convey some kind of rhetorical emphasis which I notice but do not feel, if you know what I mean. It has a sort of slangy feel. Is there a story here?

Also, it often consumes any article that might otherwise precede the next noun. It suppresses a preceding preposition. In back of is written simply back of.

_{*. I'm an introverted intuitive and often I cannot access my full memories on a topic at first. So I don't presently remember which works they are, but if nobody freaks out about that and changes the mood of the room on me, I may very well remember shortly.}

Answer 1

The OED has this:

15. back of: back from, behind. (Esp. in U.S.). Cf. in back of at BACK n.1 23g.

Their first, last and a middling citation are:

1694 in Cal. Virginia State Papers (1875) I. 44 We Ranged on Ackoquane and so back of the Inhabitants and ye So[u]th.

1840 R. H. Dana Two Years before Mast ix, The mission stands a little back of the town.

1953 M. Laski Victorian Chaise Longue 21 No one could live there, back of the railways, down by the canal.

There's also the remote back of beyond, first attested 1816.

Answer 2

We use the expression in the UK. It has the same meaning as "on the strength of", or "as a result of".

As an example:

Sam got the lead role in Macbeth on the back of his performance in Hamlet.

As to its origin, I couldn't say. However, it reminds me of the "standing on the shoulders of giants" phrase attributed to Newton. He could have said: "I got where I am today on the back of loads of people before me."