The Merriam-Webster dictionary says that “A1” means “of the finest quality” and it says that the term was first used in the year 1801 (with no reference):
However it does not give any information about the origin of the word.
Wiktionary says the phrase comes from the classification of ships. A1 ships were the best, A2 and A3 were not as good. However they say the first use was in 1837 (again with no reference): https://en.wiktionary.org/wiki/A1
This page: https://www.thehindu.com/books/know-your-english/know-your-english-meaning-and-origin-of-a1/article6210180.ece, says that a ship is A1 if both the hull and the equipment are in excellent condition.
So by doing a lot of research, I have found out that the term “A1” comes from a ship classification dating back to ~200 years ago, but two dictionaries have given different dates for the etymology (1801 and 1837) and neither give any reference! Does anyone know a reference that would help me study better the origin of this term?
It’s from Lloyds register of shipping. They surveyed and cataloged ships and constructed a database of most of the ships in Europe.
There is an image from a single surviving list from 1769 that shows the classifications, including a1 (little a, as opposed to big A). And there is a discussion of the classification scheme and its notations in the same book.
The book is – Annals of Lloyd’s Register, 1884
Being a Sketch of the Origin, Constitution, and Progress of Lloyd’s Register of British and Foreign Shipping
It can be looked at in part as a guest at https://www.forgottenbooks.com/en/books/AnnalsofLloydsRegister1884_10627433
The pages of interest are 6 through 8. It says the notation changed from AG to a1 (later A1) between 1764 and 1768.