John Moir Jr, a member of an old Massachusetts family, was bitten by the old car bug quite early, having a 1912 Brasier as his first car, followed by a 1930 Cadillac V16 roadster in which he commuted from the family home in Brookline, MA, to Harvard University across the river in Cambridge. Parking such a majestic car was a problem, and a AC 2-litre "Buckland" tourer was acquired for its more "parkable" size.
Moir continued to add to his collection and one day, his wife of 52 years, the late Heather Moir, "took notice of three cars in the garage: an A, a B, and a C. 'Since you have those, you might as well finish the alphabet,' she told him." And so he did.
"What was probably intended as a litle private jab from wife to husband took rapid hold in John Moir's mind, and by 1999, he had completed a collection of 26 cars, one for each letter of the alphabet, from A to Z. It is believed that this is the only "A to Z" collection in the world... the collection also spans the entirety of the 20th century, with the oldest item built in 1900 and the most recent in 1999."
The RM digital catalogue can be found at this LINK and is well worth perusing. As the collector car auction field has become so lucrative, the quality of their auction catalogues has skyrocketed, with RM's work being particularly impressive. The quality of photography and text of this catalog and others rival what is found in the very best magazines.

John Moir Jr in his "college car" in 1950.