As chairman of the then-powerful Berkeley Civic Arts Commission, McDuffie was politically formidable. He later helped establish both the California state parks and the East Bay regional parks systems and served as president of the Sierra Club and chair of the Save the Redwoods League. In 1913, he convened a meeting at the Claremont Hotel to discuss the creation of zoning laws in Berkeley that would exclude people of color. It was one of the first meetings of its kind in the nation. A flier for the meeting read, “The location of one laundry near Dwight Way … deteriorated that neighborhood until only negroes and Orientals would rent nearby buildings.”

In 1916, McDuffie convinced the Berkeley City Council to approve an exclusionary zoning ordinance, arguing that it was needed for “protection against the disastrous effects of uncontrolled development,” according to a 2013 historical report in The Concord Review. The city expedited the ordinance “to prevent a prominent negro dance hall from locating on a prominent corner” in the Elmwood, according to the report.

A year later, in 1917, the U.S. Supreme Court outlawed city zoning rules based on race, but in the decades afterward, Berkeley and Oakland adapted by banning apartment buildings in neighborhoods like Rockridge, Elmwood, and areas of Temescal and only allowing single-family homes, under the assumption that low-income people would not be able to afford to buy a house in an upscale area. Real estate agents and banks then kept the neighborhoods white for years through red-lining practices—refusing to sell homes or offer mortgage loans to people of color in traditionally white areas.

In the 1950s, ’60s, and early ’70s, Oakland and Berkeley finished walling off white neighborhoods from development through the implementation of strict building-height limits and parking mandates that effectively made apartment buildings impossible to build.

Today, there is no evidence that racism still plays a role in opposing new dense housing in Rockridge, parts of Temescal, and in neighborhoods like Elmwood and Claremont. Instead, residents of those areas cite concerns about parking and traffic, “greedy developers,” and “shadows” cast by tall buildings as reasons to oppose new housing.