It was an astonishing episode that has been largely forgotten. In 1963, just as the rest of Britain was embarking on a sexual, social and musical revolution, the city of Bristol was fighting a battle that seemed to belong to another age and another country. The city's bus company, with the open connivance of both management and unions, was operating a colour bar. It was not passengers that were the target, but drivers. Not a single black driver was employed, in case the job prospects of white drivers were affected.
The result was a boycott of the buses by local campaigners, which made headlines around the world.
This is one of the narratives that will be recounted in a new £27m museum, M Shed, in the restored Bristol docks. The museum will tell the stories of the city when it opens this Friday, and the stories of Bristol are many, as the objects in the museum will testify.
There will be historic steam locomotives and harbour boats, models and props for the Wallace and Gromit films, a Technics record deck, spray-painted pink, used by the local band Massive Attack, and from a much earlier time there will be tokens used by abolitionists to gain support for the abolition of slavery.
Bristol played a major role in the transatlantic slave trade, though only in very recent times has the city been ready to acknowledge it. Tony Benn, who was a Bristol MP for most of his parliamentary career, told me: "Bristol was a great slave centre, but people never mentioned that. They were ashamed of it."
Benn was also involved in bringing the colour bar on the buses to light, after being approached by a young local activist, Paul Stephenson. He says: "Paul got the idea from the bus boycotts in America. I got involved, which made my own union, the TGWU, a bit cross. And I got on to Harold Wilson and he supported the case. I think what really helped was Wilson. Once the leader of the opposition, soon to be Prime Minister, had embraced the case it made a big difference."
Stephenson, who still lives in Bristol, recalls: "I led the boycott. I saw it not so much as a political fight but as a moral way of how we had now got to see ourselves. I'm afraid that different sections of the leadership of the TGWU caved in to reactionary forces, and the boycott took five months to achieve its aim. What was so ridiculous was that Bath, next door, did not have a colour bar."
Though the boycott has been portrayed as being solely about Afro-Caribbean drivers, in fact the first driver to get a job because of the boycott was a Sikh.
Just how entrenched attitudes were in the city at the time of the boycott is illustrated by Tony Benn recalling that the Bishop of Bristol told him that Stephenson was a "troublemaker." Stephenson, a youth worker when he led the boycott, is now an OBE.
M Shed will display 3,000 Bristol artefacts and stories, showing a city that not only played a role in the slave trade but was also a major industrial centre, with Rolls-Royce and Concorde using it as a base. Now much of that industry has gone, and the city is more a centre for finance and the arts.
The new museum, to which admission will be free, will be notable for its look. Designed by LAB Architecture Studio, which is famous for Melbourne's Federation Square, M Shed will include three permanent galleries, a glazed rooftop extension offering panoramic views across the harbour and a functioning train shed – after all, the museum is housed in landmark 1950s transit sheds.
But it will be just as notable for bringing a city back into contact with its chequered past.