WASHINGTON • The Ferguson shooting death of Michael Brown that has roiled the St. Louis region and focused the nation on race relations was a result of “racially explicit, purposeful, federal, state and local government policy that lasted over a century,” a scholar for a Washington think tank said Thursday.

Richard Rothstein, a research scholar for the liberal Economic Policy Institute, said government policies at all levels dating to the early 20th century on labor, housing and other economic issues led to racially segregated enclaves and unequal economic opportunities that still exist in American cities.

“This is not just a St. Louis story,” he said during an Economic Policy Institute forum on Ferguson.

Rothstein has written a lengthy study identifying what he calls the root causes of what led to the death of Brown, 18, who was shot by Ferguson police Officer Darren Wilson in August. He said he did it, in part, to dig deeper than the white flight and “private prejudice” reasons that have populated many analyses in the three-plus months since Brown’s death.

“It struck me that this explanation betrayed a complete lack of historical knowledge,” he said, decrying the lack of knowledge by many Americans of the Jim Crow and government policies of the early- and mid-20th century that he said still resonate today.

“It was a complete, if I might say, whitewashing of how Ferguson became Ferguson.”

Rothstein said the St. Louis region — and other American urban areas — can trace many current racial challenges to specific government policies, starting with President Woodrow Wilson’s decision a century ago to resegregate the federal work force. Rothstein said institutional segregation intensified in federal public housing and mortgage policies through the mid-20th century, and in federal jobs policies leading into and during World War II that denied blacks the same opportunities as whites. Local zoning and housing development policies mid-century further solidified segregation in parts of the St. Louis region, he said

Rothstein and Sherrilyn Ifill, the NAACP’s Legal Defense Fund’s director-counsel, spoke at the Economic Policy Institute Ferguson forum.

Ifill said that the violence and unrest surrounding Brown’s death is a symptom of a far larger problem than police-community relations.

A local grand jury, the St. Louis County Police, and the U.S. Department of Justice are investigating the shooting, and the Justice Department is also looking into the patterns and practice of Ferguson’s police department.

But Ifill said that whatever the grand jury decides will not address the underlying problems.

“Even if Darren Wilson was indicted, even if Darren Wilson was convicted, would that respond to the full set of conditions in Ferguson?” she asked. “Would that really respond to the lack of real economic infrastructure? Would that have created an opportunity for Michael Brown, had he lived, to have a full education, to be fully employed in ways that would allow him to have a full, successful, and prosperous life?”

Later, on Capitol Hill, Sen. Claire McCaskill, D-Mo., said she believed that the Brown shooting had “solidified a lot of discontent, reasonable discontent, about some of the policies of this country, particularly when it comes to the criminal justice system.

“But on the other hand, it also is demonstrating the kind of robust support we have in this country for our police officers,” she continued. “And it is navigating those two issues that is such a challenge — making sure that we support our police but also hear the protesters, because it is Mike Brown, but it is also much bigger than Michael Brown.”

McCaskill and Sen. Roy Blunt, R-Mo., had lunch on Wednesday, and Ferguson was a prime topic, Blunt said. Later, they participated in a conference call with Attorney General Eric Holder and Missouri state and local officials, to discuss preparation for the grand jury’s decision.

Blunt said he urged Holder to expedite the Justice Department’s investigation as much as reasonably possible. The Justice Department says its investigation is on its own timetable.