Since it is a slow news week, let me just post this item from Peter Sefton, who filed the nomination for the landmarking of the Langston and Slater Schools. (Peter’s post is from the Historic Washington list at Yahoogroups.)
Stars of David medallions on Langston School
Posted by: “psefton @ comcast.net” psefton @ comcast.net douglassefton
Mon Dec 19, 2011 4:15 am (PST)
In preparing the DC Inventory nomination for the Langston and neighboring Slater Schools, I found no evidence that the “Star of David” window was intended to have any denominational significance. This star pattern is an ancient generic symbol for health and good fortune in a number of eastern religions, and this is probably why Appleton P. Clark used in it his design for the school in 1902.
Like the earlier Slater School, Langston School was built expressly for African-American students. Its location on what eventually became a sort of campus with Cook, M.M. Washington, and Slater grew out of a very ugly and shameful controversy between white residents of such nearby neighborhoods as Eckington, and the Board of Education. The nomination describes this in some detail.
The Slater and Langston Schools were listed on the DC Inventory of Historic Sites on October 27th and their nominations are now being forwarded to the National Park Service with a recommendation for inclusion in the National Register of Historic Places. As far as I know, the schools are still owned by the city, although a number of organizations had utilized them in recent years.
Peter Sefton, Chair
Landmarks Committee
DC Preservation League
Bates Area Civic Association 
See the Washington Post article from 1901 “OPPOSE NEGRO SCHOOL :Eckington Citizens Object to Change Made in Site. ASK COMMISSIONERS FOR DELAY District Will Hare Power to Condemn Site After July 1, Under New Law, and Citizens’ Association Requests that Matter Be Laid Over — Present Colored Schools Filled with Pupils from Other Sections — Hog-driving Nusiance Denounced.. (1901, March 26). The Washington Post (1877-1922),10. Retrieved December 20, 2011, from ProQuest Historical Newspapers The Washington Post (1877 – 1994). (Document ID: 257061902).” If you have access to ProQuest.
It seems the white residents represented by the Eckington Citizens Association opposed the building of another school for African American children in 1901, a year before the school was completed and opened.
Here are two more follow-on comments posted at the Historic Washington list on the Stars of David symbols at the Langston, Slater Schools:
Posted by: “RayM“ mrrayj @ gmail.com
Sun Dec 25, 2011 5:47 am (PST)
I snapped an image this evening in the dark. The three medallions are prominent architectural features. I spoke with a staff member of the Jewish Historical Society this afternoon who reiterated the lack of evidence that this school had any association with city`s Jewish community. Peter may be right about the symbol`s non-Jewish significance, as the school was built in 1891-2, when the Zionist movement, which adopted the Shield of David as its symbol for the return to Israel, was relatively new. Otherwise, the symbol, with Kabbalic significance, was little used in public architecture. Still, I remain skeptical that it was used innocently. The same goes for the swastikas worked into the half-timbered (Fachwerk) and stucco house on 1754 Euclid Street in Adams Morgan.
Ray Milefsky
Posted by: “psefton @ comcast.net“
Sun Dec 25, 2011 5:51 am (PST)
The Langston School was built in 1902. The neighboring Slater school was built in 1890-91. However, there is still no link other than to a generic good health symbol.
1754 Euclid was permitted in 1900, which would be awfully early.
Peter Sefton