On the campaign trail, President Obama has been reminding himself just how far his country has come in terms of civil rights.
The US premier visited the bus made famous by Rosa Parks when she refused to give up her seat for a white passenger in 1955.
From then on she was known as "the first lady of civil rights" and "the mother of the freedom movement".
"I just sat in there for a moment and pondered the courage and tenacity that is part of our very recent history," he said.
"But [it is also shared by a] long line of folks who sometimes are nameless, oftentimes didn't make the history books, but who constantly insisted on their dignity, their share of the American dream," added the president.
The vehicle is currently at the Henry Ford Museum in Dearborn, where he was holding a fundraiser.
It was originally in circulation in Alabama when Rosa, who died at the age of 92 in 2005, made her historic stand.