The Country squire was always amongst the biggest, heaviest passenger cars of every model year. Their size reached a peak in the mid-70s. They were fitted with huge V8 engines ranging from a standard 351 windsor to a beastly 460 (7.5L) V8 that was the largest engine ever mass produced. The big engines were choked by emissions requirements starting in the early 70s and got atrocious gas milage.
(Disclaimer, I own a Country Squire, and I believe it to be the most badass car ever built.)
The O'Doyle Family from Billy Madison own a Ford Country Squire and drive it off a cliff toward the end of the movie.
The "Family Truckster" from National Lampoons Vacation is a heavily modified Country Squire.