Way back in the Dark Ages of plastic modeling (i.e., the early fifties) Revell issued a series of small horse-drawn vehicles on the scale of 1/40. (The first ones actually originated with a company called Miniature Masterpieces, from which Revell bought the molds.) They included (let's see if I can remember all of them) an American stage coach, a covered wagon, a buckboard, a chuck wagon, a medicine wagon, an eighteenth-century English stage coach (my favorite), a Roman chariot, the State Coach of England (issued to coincide with the coronation of Elizabeth II), and what was called a "Lafayette Coach." The latter sounds like about what you're looking for.
Then there was a series of horse-drawn fire engines, which have become among the most sought-after kits among collectors. Legend (unconfirmed) has it that the molds for those got destroyed. And Revell contracted with the producers of the TV show "Death Valley Days" to produce a model of the mule team publicized by 20-Mule-Team Borax (complete with all 20 mules).
The other kits have reappeared from time to time under various other labels: Adams, Athearn, LifeLike, MPC, and maybe a couple of others.
The quality of these kits varied a little (they were released over a period of more than a decade), but generally they were beautiful. Each came with several exquisitely-executed figures - horses, people, and sometimes other critters. The chuck wagon, for instance, featured two horses, a calf, a dog, and three humans, all intended to be arranged in a small diorama on the included base. The State Coach had eight horses with riders, and recognizable miniatures of Queen Elizabeth and Prince Philip. The "Lafayette Coach" had two horses, a driver, and two passengers: a military officer in a cocked hat and a woman with an umbrella.
In the past few years I've managed to find examples of all but the American stage coach, the buckboard, and the medicine wagon - all at fairly reasonable prices. Possible sources include old hobby shops, e-bay, and dealers in old kits. I don't normally consider myself a kit collector, but in this case I've made an exception. (I've finished the English stage coach, and plan to do the others eventually. To do them justice takes a long time.) To my mind these kits are real specimens of the "golden age of plastic modeling."