Colin will be along soon but my understanding is that Hebden Bridge started as just that; a bridge over the river for the main packhorse trunk route to the wool market at Halifax.
That's true. The little cobbled packhorse bridge over Hebden Water is a replacement for the original medieval bridge.
I read that the valley used to be very swampy so the packhorse trails stayed high where possible.
The While Lion Hotel is an old coaching inn built in 1657. I would guess that the packhorses were brought though Midgley and Old Town, down to the White Lion. From there they would cross the old bridge and head up the Buttress to Heptonstall. (Or make the journey in the opposite direction towards Halifax.)
Being a natural stopping point it wouldn't have been long before inns followed and then the new manufactories, which would have been beside the river for the water and the power. That's what makes me think all the riverside buildings would have been industrial or commercial, not the comfortably furnished and carpeted dwellings, cafes, pubs and shops we have now.
Most of Hebden Bridge was built surprisingly recently! My house is on a little cobbled back street but it wasn't built until 1888, about the time that many buildings in the town were. There certainly weren't a lot of buildings here before the start of the 19th century.
By contrast, Heptonstall village (on a hill overlooking Hebden Bridge) has many 500 year old buildings.
The sudden expansion of Hebden Bridge in the 19th century was due to the construction of many water-powered mills. If you go for a coffee in the cafe at 'Innovation', take a look at the posters on the walls depicting the history of the local mills. Many of those mills no longer exist.
Later, steam power was used. At one point there were supposed to be about 500 mill chimneys in the Calder Valley and the air pollution was horrendous. Housewives would hang out their washing to dry, then the wind direction would change and would cover the washing with smuts.
I read that Hebden Bridge was considered such a horrible place then that misbehaving children were threatened with being sent here!
"Get thee t'Hebden Bridge!"
I just discovered what used to be on the Heptonstall side of the old bridge -
Buttress Brink!
"Most problematical of all was Buttress Brink, where occupants had to walk through a gloomy ground floor tunnel still lit by gas lamps, climb steep steps set into an almost vertical hillside, then cross bridges spanning the gaps between hillside and property. Needless to say the homes within boasted no modern amenities such as bathrooms and toilets; the kitchens, small and cramped, had only a single cold water tap over a stone sink."
There is a big picture of Buttress Brink
here, and it includes the original Hole in the Wall Inn.