Can the end of double spacing after periods be dated?

Question

From this Slate article:

Hundreds of years ago some typesetters would end sentences with a double space, others would use a single space, and a few renegades would use three or four spaces. Inconsistency reigned in all facets of written communication; there were few conventions regarding spelling, punctuation, character design, and ways to add emphasis to type.

[…]

Every modern typographer agrees on the one-space rule. It's one of the canonical rules of the profession, in the same way that waiters know that the salad fork goes to the left of the dinner fork and fashion designers know to put men's shirt buttons on the right and women's on the left. Every major style guide—including the Modern Language Association Style Manual and the Chicago Manual of Style—prescribes a single space after a period. (The Publications Manual of the American Psychological Association, used widely in the social sciences, allows for two spaces in draft manuscripts but recommends one space in published work.) Most ordinary people would know the one-space rule, too, if it weren't for a quirk of history.

However, a double-space after period rule is still the default in some software, and most famously in TeX. This implies that the transition may not be as “complete” as the Slate article implies. So, my question is: can we somehow date the end of the double-space?

Answer 1

If you have an account at the AP Style Guide you'll see that this process is already in the works.

It's part of AP style to not put 2 spaces after a period.

http://www.apstylebook.com/online/index.php?do=entry&id=3544&src=AE

Answer 2

Historical typesetting practice put more space after a sentence-ending period than between words or after abbreviations. Typewriters didn't offer variable width spaces, but putting two spaces after a period left an amount of space that was roughly comparable to typesetting practice.

The change in typographic practice is directly attributable to the rise of automated typesetting equipment which was unable to handle the larger spaces properly. The lack of a widespread revolt when newspapers eliminated the extra space after sentence-ending periods subsequently allowed that style to become "accepted". Publishers didn't mind the change, since using a wider spaces after sentence-ending punctuation requires that the typesetter accurately recognize which punctuation is supposed to end sentences; making all spaces the same width avoids the possibility that a typesetter might get it wrong.

Personally, I think it's unfortunate that typographical laziness has prevailed, especially given that computers would be have no trouble handling sentence spacing properly when two spaces are used after punctuation, but cannot be completely accurate otherwise unless given explicit instruction. Since it's much easier for an author to simply hit the spacebar twice after sentence-ending punctuation than to figure out when a computer might otherwise get confused and add the appropriate overrides, the elimination of the extra spaces increases the likelihood of typographical mistakes with documents set according to traditional spacing practices.