Detailed Instructions: Generate a correct and concise answer for the question based on the words in the context.
Q: Context : John Kelvin Koelsch (December 22, 1923 -- October 16, 1951) was a United States Navy officer and a recipient of America's highest military decoration -- the Medal of Honor -- for his actions in the Korean War.
Question : In what military branch did John Kelvin Koelsch serve?
A:
United States Navy