But from the very beginning the street has defined the region - and in fact the entire state - metaphorically as well as factually.
In 1785 it was drawn as the baseline for maps of the entire territory on Michigan. And while Detroit's annexation of land left its boundaries jagged along its other borders, the northern border of Eight Mile Road remained a straight line.
The city's racial tensions have long roots.
As southern blacks moved north to cities like Detroit in the 1930s and 1940s, many whites simply left the city and built communities that developed exclusionary policies, says Robin Boyle, an urban expert at Wayne State University. Michigan law allowed for particularly strong home rule, which, he says, included "conspiracies particularly between the real estate and finance industries."
The city's population shifted from 43 percent black in 1970 to 63 percent in 1980. And though federal laws eventually outlawed discriminatory housing practices, the history already in place in Detroit has been hard to overcome.
"What creates the high level of segregation in this area is that whites don't stick around long enough for integration to occur," says Cliff Schrepp, executive director of the Fair Housing Center of Metropolitan Detroit. "When blacks come into the neighborhood, they leave."
Even with laws in place, subtler exclusionary real estate practices still go on, says E'toile Libbett, president of the Detroit Board of Realtors. Racism is something that is felt if not always seen.
"There are a lot of stories and it is done much more quietly now," she says. "If something like a black couple look in a white neighborhood and they hear, 'Oh, there's a sales agreement on that [house],' and then two or three weeks later it is still on the market and nothing has happened."
Beyond rumor there are occasional hard-fact cases.
Just two years ago, a local real-estate agent was honored for reporting a white seller, a former state judge, who refused to sell to a black family in nearby River Rouge. The seller lived in another home on the street and did not want the first property to go to a black family.