John Scott Napier was the second son of Francis and Nina Napier. Francis, also known as Lord Napier, served as the British Minister to the United States from 1857-1859. During this time the Napier family lived in Washington DC and were close with the Seward family. Fanny Seward recounts taking dancing lessons with John and his brothers in her 1858-1859 diary, and also seeing them during social visits. 

John appears to have spent much of his life in the UK after moving back in 1859. He spent much of his career in the military and died in 1938 on the Isle of Wight.