This term refers to a car big enough to haul people and luggage to and from a railway station. Originally, station wagon referred to horse-drawn carriages. From the Hub News of 23 May 1894:
Business has been fairly good this spring...Traps are in most demand, next come buggies, cutunders, and business rockaways or station wagons.
By 1904 the term was being used in reference to automobiles. From Motor World of 21 January of that year:
The station wagon is a new model exhibited the first time this year.
The British equivalent of the term, estate car, is much more recent. It only dates to 1950. From Motor Industry of July of that year:
Latest car price list...Standard...Vanguard saloon...Estate car.
(Source: Oxford English Dictionary, 2nd Edition)
Copyright 1997-2013, by David Wilton