vonbernstorff

This is apparently the son of the German ambassador to the US, Johann Heinrich von Bernstorff. There was a German diplomat of the same name a hundred years earlier, and the ambassador himself would have been about fifty at the time of this photo. I think the date on the right side says "12/11/17," which coincides with this article about his controversial marriage in the NYT: query.nytimes.com/gst/abstract.html?res=9402E0DB1E3AE433A...

This appears to be (left to right), unknown; (German) Captain Ludwig Ritter von Mann of the Moltke [1]; (US) Rear-Admiral Aaron Ward (1851-1918)[2], Acting Commander of the American Fleet; Count Von Bernstorff, German Ambassador to the United States; and (German) Rear Admiral Hubert von Rebeur-Paschwitz, Commander of the German Squadron during the Spanish-American War, on the occasion of the visit of the Kaiser at Kiel's fleet of three ships to New York City in June, 1912. – New York Times

Second from right in the photograph, and standing at the rear of the main grouping is Lieutenant Work. See comparison photograph here: www.flickr.com/photos/library_of_congress/3512136031/

and see

There are numerous pictures taken of people coming down these steps. The African American man seems to be the announcer. Since there are other pictures in this bunch having to do with Taft's inauguration I wonder if that is what these are from.

The man with the megaphone is also in these photographs:

   

This event is probably the Diplomatic Corps Reception at the Pan American Building, Washington D. C. on New Year's Day 1913. These distinctive gates are at the front of the Pan American Building, Washington D.C.. See this photograph for confirmation : www.flickr.com/photos/library_of_congress/2179870664/ John Barrett, a very experienced diplomat, was Director General of the Pan American Union (and its' predeccessor) from 1907 to 1924. [ ref. en.wikipedia.org/wiki/John_Barrett_(diplomat) ] On New Year's Day 1913, President Taft hosted his New Year's Day Reception at the White House, which many of the Diplomatic Corps attended. [ query.nytimes.com/gst/abstract.html?res=9900EEDA123BE633A... ] However, on that same day and also referred to in that New York Times article: "Second only in importance to the White House Reception was the breakfast at the Pan-American Union Building where the Secretary of State and Mrs. Knox entertained the members of the Diplomatic Corps and their families, withthe members of the Committees of the House and Senate dealing with our foreign relations. To welcome these guests the Secretary and Mrs. Knox dropped out of the White House receving line after the passing of the Supreme Court. In the Pan-American Building they received standing at the head of the marble stairway overlooking the patio. The breakfast was served in the Hall of the Americas, regarded as the most beautiful formal apartment in Washington." There is also a photograph of P. C. Knox, the Secretary of State with his wife and the same herald with megaphone on the same steps as those depicted above here : www.flickr.com/photos/library_of_congress/3314477848/

en.wikipedia.org/wiki/Organization_of_American_States has a second photo that shows the gates of the Pan American Union Building more clearly -- to confirm lifeasdaddy's hypothesis. See en.wikipedia.org/wiki/File:OAS_Building_-_DC.jpg

Johann Heinrich von Bernstorff (1862-1939), German ambassador to the U.S. and Mexico, 1908 to 1914. en.wikipedia.org/wiki/Johann_Heinrich_von_Bernstorff#Amba...