Here's a puzzle that W. Edward Orser presents to students:
Imagine an American community of 20,000 people. Then imagine the same community 10 years later. Its population remains 20,000, but almost none of the residents are the same ones who had lived there 10 years before. What happened?
The students sift through environmental and economic catastrophes that could have caused such a dramatic population shift. Then they stumble on the obvious, American answer: Black people moved in, and white people moved out.
Posing the question, Dr. Orser, 53, an American Studies professor at the University of Maryland Baltimore County, has a particular community in mind -- Edmondson Village. The West Baltimore neighborhood went from all-white to nearly all-black in a decade, 1955-1965.
Now Dr. Orser has written a book, "Blockbusting in Baltimore: The Edmondson Village Story," about that social upheaval, a phenomenon common in cities across the nation.
A reception honoring current and former residents interviewed for the book will be held at 2 p.m. today at the Edmondson Village branch of the Enoch Pratt Free Library.
Ann Lansinger, 50 and white, grew up in the community until her parents moved out in 1962. She remembers a cozy rowhouse neighborhood that climbed Edmondson Avenue from the Gwynns Falls bridge west to the Colonial-style Edmondson Village Shopping Center.
"The mothers were home all day, the world was the back alley, your friends were the neighborhood children, and the schools were so close that you walked home for lunch," Ms. Lansinger said.
Betty Martin, 60 and black, moved to Edmondson Village in the mid-1960s. She recalls an equally pleasant community: sturdy, spacious rowhouses shaded by suburban-style greenery and served by the well-stocked shopping center.
But those memories are marred by a decade of change and fear. Nearly 40 years later, the racial transformation of Edmondson Village is still sensitive.
Real estate speculators, known as "blockbusters," helped drain Edmondson Village of all but about 400 white residents and stocked it with blacks eager to escape their poor neighborhoods.
Typically, Dr. Orser says, blockbusters would pay one white homeowner handsomely to sell and "break the block." After a black family arrived, the blockbusters would warn whites to sell quickly before more blacks came and property values plummeted.
It was a self-fulfilling prophecy. As whites' homes flooded the market, speculators paid less and less for them. But they charged blacks, a captive market unable to buy homes in most areas or obtain bank financing, a premium to integrate Edmondson Village. Some people called it "the black tax."
"The blockbusters had an uncanny understanding of how American racism could be turned to profit," Dr. Orser said. But he is reluctant to cast them as the only villains of the piece.
The pent-up postwar demand for housing, the rapid development of all-white suburbs, the mainstream real estate market's refusal to deal with blacks, whites' racism and blockbusters' panic-peddling (outlawed in 1968) conspired to trans form Edmondson Village and other places.
Whites and blacks often "passed like ships in the night," he said. Edmondson Village whites, an insulated, middle-income group, assumed the black newcomers were lower-class.
But the black pioneers were remarkably like the whites, Dr. Orser says, except that black women tended to work more outside the home to make ends meet.
Marguerite J. Campbell, 78, moved in south of Edmondson Avenue in 1956. She recalls scattered resistance to blockbusting, including "This House Is Not For Sale" signs. William Donald Schaefer, then a councilman and to this day an Edmondson Village homeowner, urged whites not to abandon the neighborhood.
But most whites fled, albeit sometimes with polite explanations.
"The woman next door to me said had she known we were as nice as we were, she never would have put up her house for sale," Mrs. Campbell said.
Betty Martin said it hurt black families to see whites flee. But blacks were used to being hurt.
"You think you've arrived, and then the for-sale signs go up. I don't say you have to like it, but what can you do?" Mrs. Martin said.
For the whites who left, the memory is also painful. Homeowners sometimes kept their leaving a secret from neighbors so as not to drive down their selling price.
Albert Koslowski, 54, who organizes Edmondson Village reunions every five years, recalls being a teen-ager "up the Village," as the shopping center was known, a 1950s setting right out of "Happy Days" or "Grease."
The "squares" -- crew cuts, plaid shirts, khaki pants, saddle shoes -- patronized Whalen's Drug Store, hogging the sitdown wooden phone booths. The "drapes" -- Elvis haircuts, silky shirts, pegged pants, suede shoes -- hung around the bowling alley, honing their toughness.
Their elders thought blacks "would never come across the bridge" over the Gwynns Falls. When blacks did move in, the neighborhood panicked, Mr. Koslowski said.
"You've got to remember our parents were from back in the Twenties. Parents would tell you blacks are no good, they're this, they're that. You start believing that. I never saw a black person until I was 8 years old," he said.
Mr. Koslowski, whose family lived in Edmondson Village from 1951 to 1964, said white homeowners took "anything they could get to get out of there. It was pitiful."
The notion of racial integration, Dr. Orser said, was "not really part of their world."