Question: When did Sobrante Park, Oakland, California witness a large migration of white residents? 
Context: Sobrante Ridge Regional Park, or simply Sobrante Ridge, is a regional park of the East Bay Regional Parks District in Richmond, California.  It covers 277 acre and protects the extremely endangered Alameda Manzanita, a native plant of the area.  The park has 2+1/2 mi of trails.The endangered manzanita grow on 9 acre . Sobrante Park is a neighborhood located in East Oakland, California, which is partially separated from the rest of the city by two railroad tracks and San Leandro Creek.  It was built shortly after World War II, first as a White-Only Lockout and then gradually becoming a White flight red-zone in the mid to late 50's, and in the early 60's it became a working-class black neighborhood.  It was projected by planners that there would be no in-road into SanLeandro's Davis St. residential area which was developed during the same period. White flight is a term that originated in the United States, starting in the 1950s and 1960s, and applied to the large-scale migration of people of various European ancestries from racially mixed urban regions to more racially homogeneous suburban or exurban regions.  The term has more recently been applied to other migrations by whites, from older, inner suburbs to rural areas, as well as from the US Northeast and Midwest to the milder climate in the Southeast and Southwest.  The term has also been used for large-scale post-colonial emigration of whites from Africa, or parts of that continent, driven by levels of violent crime and anti-colonial state policies. New Orleans English is American English native to the city of New Orleans and its metropolitan area.  Native English speakers of the region actually speak a number of varieties, including: the variety most recently brought in and spreading since the 20th century among white communities of the South in general (Southern U.S. English); the variety primarily spoken by black residents (African American Vernacular English); the variety spoken by Cajuns in southern Louisiana (Cajun English); the variety traditionally spoken by affluent white residents of the city's Uptown and Garden District; and the variety traditionally spoken by lower middle- and working-class white residents of Eastern New Orleans, particularly the Ninth Ward (sometimes known, since at least the 1980s, as Yat).  However, only the last two varieties are unique to New Orleans and are typically those referred to in the academic research as "New Orleans English."  These two varieties specific to New Orleans likely developed around the turn of the nineteenth century and most noticeably combine speech features commonly associated with both New York City English and, to a lesser extent, Southern U.S. English.  The noticeably New York-like characteristics include the NYC short-"a" split system (so that "mad" and "map", for example, do not have the same vowel), the diphthongizing of to [ɔə] or [ɔʷ] , non-rhoticity, "th"-stopping (so that, for example, "those" may merge with "doze"), and the recently disappearing coil–curl merger.  Noticeably Southern characteristics include the fronting of and possible monophthongization of (just these features, plus non-rhoticity, often characterize the Uptown accent). The gentrification of Atlanta has been the source of both praise and condemnation.  Gentrification of Atlanta's inner-city neighborhoods began in the 1970s, and it has continued, at varying levels of intensity, into the present.  Many factors have contributed to the city's gentrification.  A major increase in gentrification that occurred in the last years of the twentieth century has been attributed to the 1996 Summer Olympics.  However, during the 2000s, Atlanta underwent a profound transformation demographically, physically, and culturally.  Suburbanization, rising prices, a booming economy, and new migrants decreased the city’s black percentage from a high of 67% in 1990 to 54% in 2010.  From 2000 to 2010, Atlanta gained 22,763 white residents, 5,142 Asian residents, and 3,095 Hispanic residents, while the city’s black population decreased by 31,678.  Much of the city’s demographic change during the decade was driven by young, college-educated professionals: from 2000 to 2009, the three-mile radius surrounding Downtown Atlanta gained 9,722 residents aged 25 to 34 holding at least a four-year degree, an increase of 61%.  Between the mid-1990s and 2010, stimulated by funding from the HOPE VI program, Atlanta demolished nearly all of its public housing, a total of 17,000 units and about 10% of all housing units in the city.  In 2005, the $2.8 billion BeltLine project was adopted, with the stated goals of converting a disused 22-mile freight railroad loop that surrounds the central city into an art-filled multi-use trail and increasing the city’s park space by 40%.  Lastly, Atlanta’s cultural offerings expanded during the 2000s: the High Museum of Art doubled in size; the Alliance Theatre won a Tony Award; and numerous art galleries were established on the once-industrial Westside. Arsenije III Čarnojević (, 1633 – 27 October 1706) was the Archbishop of Peć and Serbian Patriarch from 1674 to his death in 1706.  In 1690, he led a large migration of Serbs from Ottoman Serbia into the Habsburg Monarchy, and this is when the Ottomans stopped recognising him, creating a rival patriarchate.  He is also remembered for attempting to get a publishing licence from the Habsburg authorities to print Serbian books but to no avail. Marin City is an unincorporated community and census-designated place (CDP) in Marin County, California, United States.  It is located 1.5 mi northwest of downtown Sausalito, and about 5 miles north of San Francisco from the Golden Gate Bridge, at an elevation of 23 feet (7 m).  Marin City was developed for housing starting in 1942, to accommodate war-time shipyard workers and other immigrants to California.  After the war, the area became predominantly African-American, as white residents were able to move freely to private housing elsewhere in Marin.  Since the 1980s, additional development has changed the makeup of the population while providing more local jobs.  The population in 2010 was 2,666.  Marin City's socioeconomic and racial makeup contrasts with the mostly wealthy and Caucasian populations in Marin County.  In 2004 the community had high levels of poverty, crime, and recreational drug use. Okhai (Urdu: اوکھائی) Memons are a large branch of Memons in India.  Named for the town of Okha, the community has spread with a large migration to Karachi having taken place in the mid 19th century. The Tragedy of Otranto took place on 28 March 1997 when the Albanian ship "Kateri i Radës" sank in a collision with the Italian naval vessel "Sibilia" in the Strait of Otranto and at least 57 Albanians, aged 3 months to 69 years, lost their lives.  The emigrants had been part of a large migration of Albanians to Italy following a popular uprising that began after the collapse of several large-scale pyramid schemes.  In order to prevent the unauthorized entry of illegals migrants into Italy, the Italian Navy set up a procedure to board Albanian vessels whenever encountered, implementing a "de facto" blockade. Murray Bishoff is a writer at "The Monett Times" in Monett, Missouri.  Formerly a contributor to "Comics Buyer's Guide", Bishoff won an Inkpot Award in 1980.  Bishoff is also known for his research and writings on the 1901 fifteen-hour lynching spree in Pierce City, Missouri, during which white residents murdered three African American residents and caused nearly 300 others to flee the city.  His writings include a series of articles published to commemorate the 90th anniversary of the event and the historical novel "Cry of Thunder".  In addition, the town's cemetery holds a marker to the event paid for in large part by Bishoff and the Pierce City Museum hosts an exhibit which Bishoff created.  He has also publicly spoken about the event to CNN and appears in a documentary about the event, "Banished: How Whites Drove Blacks out of Town in America".
Answer: mid to late 50's