After a series of big-hitting attractions – the bike shop where the Wright Brothers built the first plane, the courthouse where Abraham Lincoln practiced law, the car which JFK was assassinated in – you don't expect to be taken aback by a mere bus.
The Henry Ford Museum just outside Detroit, and the adjoining Greenfield Village, pack in so many hits of modern history that it's surely the greatest museum in the US. But it's the simple, old-fashioned bus that makes the hairs stand on end.
The colour scheme's a jaunty green and orange, while the sign at the top marks out the destination as Cleveland Avenue.
Cleveland Avenue no longer exists in Montgomery, Alabama. It was renamed in 1965, in honour of a former passenger on this very bus. That passenger was local seamstress Rosa Parks, who on December 1st 1955 refused to leave her seat to allow a white passenger to sit there. The bus driver called the police, and Parks was arrested. She was later found guilty of disorderly conduct and violating a local ordnance.
This was the beginning of the Montgomery Bus Boycott, in which the black residents of Montgomery refused to ride on the city's buses. The boycott lasted over a year, until the US Supreme Court ruled that racial segregation on buses was illegal, and the segregated seating policy was abandoned.
Parks' polite refusal to move was a brave act in itself, but it sparked something much bigger. It is generally seen as the spur for the organised Civil Rights movement in the US.
Leadership was required to maintain the boycott, and four days after Parks' arrest, the Montgomery Improvement Association was formed. Elected as its president was Martin Luther King Jr, the man who would later become the global figurehead of the Civil Rights Movement. The wheels of the bus had stopped, but the wheels of change had been set in motion – and the 1964 Civil Rights Act eventually outlawed all discrimination based on race, gender or religion.
Almost as interesting as the tale of how one woman's refusal to be intimidated by a bus driver is the story of how the bus was tracked down and ended up in the Henry Ford's collection.
The bus company sold it off in the 1970s, but the man who bought it had no documentary evidence that it was the Rosa Parks bus. Donna Braden, the museum's 'curator of public life', says: "The bus was really just a shell that he stored things in. He'd stripped the inside and thrown away all the seats."
When it came up for auction in 2001, the auction house knew vague family stories wouldn't quite cut it as evidence. Luckily, employees managed to track down a scrapbook put together by a bus station manager. He had collected a series of articles about the bus boycott
Braden says: "On one of the pages, which was right when the Rosa Parks incident happened, he wrote down the actual number of the actual bus and the name Blake - the name of the bus driver."
After comparing the number of the bus to check they matched up, and getting a forensics expert to authenticate the paper and handwriting, there was sufficient proof.
The Henry Ford put in the highest bid at auction, then spent over $300,000 restoring the bus. Original parts and furnishings were used where possible, while parts from identical 1948 buses were used to fill the gaps. Lovingly refurbished, the bus now stands unobtrusively amongst a sea of classic cars.
Almost 60 years on from the Montgomery Bus Boycott, the doors of the vehicle where it started stand permanently open. Anyone of any race, gender or religion can step inside and sit down - in any seat they choose.
The writer paid for his own travel.
The Henry Ford museum (thehenryford.org) is in Dearborn, a suburb of Detroit. It's 22km out of the city centre. It's best driven to – public transport is dismal. Opening hours are 9.30am-5pm.