 
 <translate> To answer the above question, the relevant sentence is: Since 1955, it has been the official residence of the United States Ambassador to the Court of St. James's.
So, the final answer is Winfield House. <ibo> Iji zaa ajụjụ a dị n'elu, ahịrịokwu ahụ dị mkpa bụ: Kemgbe 1955, ọ bụ ebe obibi nke onye nnọchi anya United States na Court of St. James. Ya mere, azịza ikpeazụ bụ Winfield House. 