I continued to do so when I posted on the web in the 1990s.
I was later told it was not necessary to put two spaces after every sentence on the web.
Two spaces after the period is a holdover from typewriters with their evenly spaced characters. Some computer fonts such as Courier also have even spacing.
Modern software has kerning which spaces characters proportionally, thus making a single space after a period more distinct and precluding the need for two spaces.
Free Republic holds a place in U.S. history related to such kerning. Freeper Buckhead exposed CBS' Dan Rather's fraudulent Texas National Guard documents for then-presidential candidate George Bush. Buckhead identified within minutes that the documents were a fraud because the IBM typewriter at the time didn't have kerning yet Dan Rather's documents did.
https://freerepublic.com/focus/f-news/3347939/posts
On a related note, it would be nice if Free Republic switched the default font from Times New Roman to a sans serif font such as Aptos, Arial, Calibri, Tahoma, etc. because it's read on a screen, not paper.
Because I use little doodads to process browser buffers, I’ve slipped into using single spaces all the time, but I used to be a two-spacer after a period at the end of sentence. And I’ve had people complain about it online, because they have some kind of OCD thing going on.
Same here. I continued to use two spaces after each sentence, long after hearing about the new one-space rule. I did not switch to one space until I read that prospective employers believe an applicant is older when they see two spaces after each sentence in a cover letter.
Everyone learned to put two spaces after a period for decades. I think that about 10 years ago that changed.
Anyhow, a “secret” told to me by an HR person recently is that is one method used to screen applicants to provide a good idea of age. Written components are scanned for 2 vs 1 spaces after a period.