Harry was born in Noel Shore, Nova Scotia, on the 4th of May 1879, and I am uncertain when he came to the United States. It is known that he enlisted in the US Navy in Massachusetts with his older brother Willard. When he deployed to Cuba in support of the Spanish-American War, Harry was a Seaman and his actions later earned him the Medal of Honor. The citation reads:

On board the U.S.S. Nashville during the operation of cutting the cable leading from Cienfuegos, Cuba, 11 May 1898. Facing the heavy fire of the enemy, Miller displayed extraordinary bravery and coolness throughout this action.

Harry received the Medal of Honor on the 7th of July 1899, along with his brother, making them one of eight pairs of brothers to receive the Medal of Honor. When he left the Navy, he had reached the rank of Quartermaster Third Class and he was married three times: first to Ella, with whom he had one son, second to Maria, with whom he had one daughter, and third to Esther, with whom he had one son. Harry Herbert Miller died on the 12th of March 1968, at the age of 88. He is buried in the Cemeterio de Tres Rios in Cartago, Costa Rica.