The ampersand (&) used to be the 27th letter of the alphabet, all the way up until the mid 1800s. I'm going to pause and let that sink in.
The ampersand is a logogram formed from the cursive forms of the letters that make up the Latin word for and - et. This is more obvious in some fonts than others. In fonts like Trebuchet, the ampersand looks much more like the word et - &.
The name ampersand is a contraction of the words and per se and, the phrase schoolchildren used when reciting the alphabet... W, X, Y, Z, and per se and. The per se, Latin for in itself, was used to indicate that the and was an item in a list, rather than a conjunction used to indicate something else was coming.
The ampersand's use, according to the Online Etymology Dictionary, goes back an old Roman system of shorthand signs called ligatures - we've seen evidence of it used as far back as the 1st century C.E.
The ampersand: far more than just the prettiest punctuation mark. It used to be a letter, dude. This would be like our great grandchildren finding out there used to be a 9th planet called Pluto.
This information comes to you from DailyWritingTips.com.