US Embassy by alucas
You might well be surprised ! Yes, the US Embassy is in Grosvenor Square. But this building at the top of Portland Place WAS the US Embassy - albeit only briefly from 1863 to 1866.I have walked past this building dozens of times, but only read the plaque properly the other day.
Henry Brooks Adams was an American historian, journalist and novelist, who was also private secretary to his father when he was United States Minister to the United Kingdom. For more about him have a look at Wikepedia