[Camillo]

It wasn't a letter of the alphabet any more than the dollar sign, the pound sign, or punctuation were letters of the alphabet. It wasn't used in words. All that happened is that someone decided to put it at the end of the alphabet song to teach it to children, and that's where it got the name.

[the_mitsuhiko]

> It wasn't a letter of the alphabet any more than the dollar sign, the pound sign, or punctuation were letters of the alphabet.

I'm not aware of historic English alphabets that include the dollar or pound sign or any sort of punctuation. On the other hand there is a lot of evidence of & being part of the alphabet. Wikipedia has or links to plenty of cases:

* Old Saxon alphabet: https://en.wikipedia.org/wiki/Old_English_Latin_alphabet#/me...

* The Dixie Primer, for the Little Folks: https://docsouth.unc.edu/imls/moore/moore.html#moore5

* Byrhtferð's Old English Alphabet: https://www.evertype.com/standards/wynnyogh/thorn.html

* My Own Primer, or First Les­sons in Spelling and Read­ing: https://shadycharacters.co.uk/2011/07/the-ampersand-part-2%C...

None of these are songs.

[chrismorgan]

Old Saxon alphabet: despite being on an alphabet page, it’s very clearly separated from the letters.

I’m not at all convinced that it was ever what you might call a letter of the alphabet. Although it seems to not have been rare to group it with the letters in some way, I have received the impression it wasn’t particularly common, and that it wasn’t how people generally thought of it. Nowadays we would draw a clear distinction between letters, numbers and symbols (maybe we have more symbols? though certainly fewer ligatures/abbreviations like Ƿᵉ), and call the alphabet just the letters, but I get the vibe that maybe “alphabet” wasn’t so strictly just the letters. But I handwave liberally and provide no sources in this mostly-uneducated suspicion of mine.

[martyvis]

I remember getting a rubber stamp set as a kid here in Australia, probably around time I started school in 1968. They definitely had an ampersand, dollar and cents stamp and even "No." (with the superscript o)

[TRiG_Ireland]

The Numero Sign, №, despite representing Latin letters, apparently arose in Cyrillic usage as an independent symbol. Most languages just use No or Nr.