Origins of the 'editorial we' and its counterpart, the 'editorial I'

There is an article on this topic in the 12 July 1823 Niles' Weekly Register (published in Baltimore, Maryland, USA), at page 289:

"THE FIRST PERSON SINGULAR." When it was resolved to published the REGISTER, in 1811, it was determined also that it should be conducted by myself, alone—and that no other person or persons, on any pretence whatever, should prescribe, dictate or suggest, [imperatively], the insertion of one line, unless in justification of some charges, or to correct some mistakes that might be made; for to these we are all liable. In pursuance of this rather "singular" notion, the first number contained an article in which, when I spoke of myself, I used the "first person" I–to shew that it was I who wrote it, and that we should not have anything to do with the management of this paper.

...

The use of "we," when a writer has to speak of himself, is often ridiculous in the extreme.

...

I cannot tell why it should seem more modest to speak falsely, affect authority or shew subserviency, by the use of we, we, we—than if to tell the truth and aim at nothing beyond it, by the use of I, I, I. At any rate, the last shall be used in the REGISTER by myself, even if there should be a partner in the concern, and the light of it be supported by the initials of my name—for my wish is, that every thing should pass for just as much as it is worth, and what it really is- and nothing more

So the Courier was not the only paper to use the singular.

However, the standard was to use the plural. For example Enchiridion clericum, or the preacher's guide (1812) says:

And always use the plural number, — we

...

Let sovereigns, speaking in the first person, use the plural number ; and let Reviewers, who exercise dominion in the empire of letters, use the plural number for the singular ; and newspaper editors likewise, to impress the public with an idea that their individual paper employs a constellation of talents, let them speak in the plural number ; but with what propriety can a preacher, addressing his congregation in his...

The History of British Journalism, from the Foundation of the Newspaper Press in England, to the Repeal of the Stamp Act in 1855, with Sketches of Press Celebrities, With an Index – Alexander Andrews

" The Printer to the Reader: " Courteous reader ! we had thought to have given over printing our foreign avisoes, for that the licenser (out of a partial affection) would not oftentimes let pass apparent truth, and in other things (oftentimes) so crosse, and alter, which made us weary of printing; but he being vanished^ (and that office fallen upon another more understanding in these forraine affaires, and as you will find more candid) we are againe (by the favour of his Maiestie and the state) resolved to go on printing if we shall find the world to give a better acceptation of them (than of late), by their weekly buying them. It is well known these novels are well esteemed in all parts of the world (but heere) by the more judicious, which we can impute to no other but the discontinuance of them and the uncertaine daies of publishing them, which, if the poste fail us not, we shall keep a con stant day everie weeke therein, whereby everie man may constantly expect them, and so we take leave. January the 9th, 1640."

One thing is herein to be observed — the editorial " we" was already adopted by " the printer to the reader." The printer was then, and continued long afterwards to be, the ostensible director of the paper ; all letters, in the news papers of a century later, being addressed " to the printer," until about 1740, when they were occasionally addressed " to the author."

It would thus seem that the practice started with printers addressing their readers. In early journalism, the printers were the directors of the publication and presumably what we call editors, today.

history of British Journalism_Dec.1,1859 Publisher: Bentley