More than 30 Shires, Shetlands, Dales and Percherons were the star attraction at the heritage line's first ever Heavy Horse Day in May 1996.
The event re-created timeless scenes demonstrating the role of the horse in transport history for passengers travelling on the 16-mile Bridgnorth to Kidderminster route.
Working horses in a range of guises and brightly-coloured harnesses were showing their power as they pulled everything from double decker buses to bakers' vans to road-sweeping carts.
Near Hampton Loade, trains slowed up so passengers could see horses chain-harrowing fields and pulling a turn-of-the century ice cream van beside the railway.
Heavy Horse day, now destined to become an annual event, re-created timeless scenes which demonstrated the role of the horse in transport history.
Horses remained the primary source of power for agriculture, mining, transport and warfare, until the arrival of the steam engine.
Horses and ponies began to be used in Britain's mining pits in the 18th century, to haul "tubs" of coal and ore from the working face to the lifts, in deep mines, or to the surface in shallower mines.
A horse named Robbie, probably the last to work underground in a British coal mine, was retired from a mine at Pantygasseg, near Pontypool, in May 1999.
The event followed the success of an `interlude with horses' at the Severn Valley Railway's Spring Steam Gala a month earlier.
"The Spring Gala proved that there is a great deal of public interest and enthusiasm for horses, especially when they are recreating scenes of `how things used to be'," said event organiser Ian Cryer, who attended with his horse Truman.
The event, which included guest appearances by the famous Bass Brewery Shires, heralded the start of a new commitment by the Severn Valley Railway to explaining and demonstrating the role of the horse in transport history.
Nostalgic sights on view also included a Suffolk pulling a hay rake and the years were rolled back at Highley goods yard by a demonstration of horse-shunting and timber-hauling by two Shires.
A number of horse-drawn rides were also be put on by the railway, including between the station and ferry at Hampton Loade.
In later years, temporary overnight stables were created at Kidderminster to accommodate all the horses.
Mr Cryer, a Bristol horse enthusiast and artist, said: “In this touch-screen age, fewer and fewer people realise the scale of the tasks carried out by horses but they made a huge contribution to the development of the empire and its economy.
The event became a popular fixture in the railway's events calendar and the 1998 event included the art of using horses to shunt railway waggons, a practice abandoned by British Rail more than 30 years earlier, was revived.
The last railway horse to be used for shunting waggons was finally retired at Newmarket in Cambridgeshire in 1967.
"The last railway horses were retired from service more than 30 years ago but their role in shunting wagons and delivering goods is probably better appreciated now than it was then thanks to the Heavy Horse Power Weekend," said Mr Cryer.
“We don’t plan to tell passengers where to look, we’d like them to discover these activities randomly, just as they might have done on any train journey fifty or sixty years ago," he added.
The nostalgic weekend celebrating the golden days of horse power was given the royal seal approval by a Queen Victoria look-alike in 2005.
The Severn Valley Railway recreated cameo scenes from the Britain of pre-war years along the heritage line and Queen Victoria - played by Sylvia Strange - and her lady-in-waiting Lady Charlotte Ponsonby were on hand to give a regal air to proceedings.
Early visitors were able to see up to 15 horses being fed and prepared for a variety of haulage tasks.
At Kidderminster, shire horses pulled a gig, representing the days when the animals transported door-to-door deliveries by the old railway companies.
Eric Sutch, from Redditch, was present with his Shire horse George, while Prince, a Clydesdale belonging to Jane Bradley, was on hand to remind visitors of the times when canal boats were towed by horses. There was also a reminder of the work done in coal mines by pit ponies.